A custom WordPress theme is one that is made for the unique needs of a specific company. This means no other business will be using the same theme, allowing the company to stand out among its competitors. Adopting a custom theme allows companies to make lasting impressions in today’s crowded digital landscape.

That’s why many businesses believe that custom WordPress themes are worth the investment

And as a WordPress developer, you may find yourself contemplating the idea of offering your services to create a custom WordPress theme. Perhaps you want to make a unique theme yourself, or you have been commissioned to develop one for a company.

No idea where to start? Well, you’re in the right place. This article will give you some practical knowledge and techniques for making one.

Whether you’re new or a seasoned developer, reading this will help you get the confidence and understanding to bring a custom theme to life.

If you want to develop a custom plugin for WordPress, read this tutorial instead.

Do’s and Don’ts of Developing a Custom WP Theme

Before you sit in front of your computer and get to work, here are some things you should—and shouldn’t—do when it comes to custom themes. Following these guidelines can help ensure that you have an efficient working process.

1. Do Planning And Research First

The first thing you need to do is research. And that means finding out who you want to serve as a WordPress developer. Once you’ve established that, that’s when you start thinking about what to include in the theme. 

Think about it: the needs of a blogger are way different from those of an eCommerce store, right? So if you want to be the go-to developer for your chosen niche, you better make sure you find out what they really need.

Now, what if you’ve been commissioned to make a custom theme by a client? You still have to do some research. They’ll likely tell you to include some features and plugins already, but you’re still the expert—don’t be shy about making recommendations based on your experience and knowledge. 

Don’t stop at just the website’s function—also find out what colors, fonts, and other appearance factors your client or the market you’re serving want to see. You’ll have more success or secure the approval faster this way.

2. Don’t Overload Your Theme With Features

After your research, you might want to ensure you’ve covered all possible requirements. So what do you do? You bloat your theme with so many features.

But don’t do this—this will affect the functionality of your theme and, of course, the overall site you’re working on. A website that’s working slowly will not make potential customers or your client happy. Avoid adding unnecessary features that may bloat your theme and impact performance. 

If you really need to, you can install additional features after. 

3. Do Follow WordPress Coding Standards

WordPress’ official document comprises a lot of information on coding standards and theme review process. Make sure to follow these guidelines by WordPress so that even in the future, your theme can be updated and secure against hackers.

4. Don’t Touch The WordPress Core 

The great thing about WordPress is that it’s open-source software. That means it can be used however you want and share your version with others. If you choose to, you can even change core files that contain the functionality of WordPress itself.

But the consensus is that you shouldn’t change WordPress core files. Doing this can make your theme vulnerable to security, compatibility, and other issues. In short, you’ll seriously mess up your theme.

We think Anthony Hortin of Maddison Designs said it best: 

In other words, stick with standard WordPress practices to avoid future difficulties with your custom theme.

5. Do Invest In Your Images, Icons, And Fonts

If you want to show your potential customers or clients that you’re worth investing in, don’t rely on low-quality stock images or fonts that everyone else uses. You’re making a custom theme, after all. Go for the best that you or your client can possibly afford.

6. Don’t Use Copyrighted Content For Free

Some of the best photos, videos, and fonts will be hidden behind a paywall, which is normal. Don’t go out of your way to avoid paying for them or getting them from pirated sources. Respect intellectual property rights and source content properly.

Remember, that’s not going to be a good look for you when you hand over your theme to a client, and they get sued for copyright infringement. 

7. Do Optimize Your Theme For Performance

Don’t stop at just making your theme look good. It also has to run well on different devices, browsers, and even screen sizes. Optimize your theme so it’s secure and loads quickly for a good and enjoyable user experience.

8. Don’t Forget To Provide Documentation

When developing your theme, document every step you take. Your documentation should be clear enough to explain the workings of your theme to anyone, regardless of their familiarity with WordPress. This ensures that even if you are no longer involved with the theme or website in the future, users and other developers can effectively manage and maintain it theme based on your provided documentation.

Guide: How to Create a Custom WordPress Theme

Now we get to the article’s meat: creating a custom WordPress theme. How does one go about it?

Well, the first thing you need to do is create a WordPress sandbox environment. 

Think of it like a live WordPress site that you can test without being afraid of breaking your site. That’s especially important if you have clients who already have a site and they just want a new one—at least you won’t be touching their actual site.

You can create a sandbox in seconds via InstaWP. While you don’t need to sign up to create one, making a free InstaWP account is better. That way, you can keep your test sites for more than eight hours. 

When you’re done creating your InstaWP account, you’ll arrive at your Dashboard:

Press + New Site or Add New +, and you’ll get options about what plugins to include in your test site.

You can install them now to avoid looking for them one by one within the WordPress menus. We do have recommended WordPress plugins to power up your site in case you’re thinking of what to install.

Once you’re done, press Create Site. This will appear:

Press Magic Login, and you’ll be taken to your sandbox site. You can now create the custom theme inside your InstaWP sandbox. 

A note: if you have the time and knowledge, you can go all out and create a custom theme from scratch. But if you’re in a hurry, you can use some of these faster methods.

Tweak An Existing Theme

One of the quickest ways to make a custom WordPress theme is to use one already available inside WordPress as the base. To do this, navigate to the Appearance menu > Themes

Click on Add New Theme to see all the available ones you can use.

Browse through the options and press Install and Activate on your chosen theme. We chose the Twenty Nineteen theme for the sake of this demonstration. Back in the Themes menu, just press Customize.

You’ll now be taken to this menu:

Now you can tweak and customize the theme to your heart’s content.

Using A Completely Blank Theme

Suppose you don’t want to start with a base theme. You want to start with a completely blank WordPress theme. Well, when you create a demo site with InstaWP, you’ll get exactly that:

So from here, just go to your Dashboard, go to Appearance, then click directly on Editor.

You’ll still be taken to the same menu where you can tweak all the parts of your website:

Use A No-Code Builder

There are plenty of no-code builders available as a plugin inside WordPress. Here’s how to access them inside your InstaWP sandbox. First, go to the Plugins Menu and click Add New.

In the next screen, search for block builder. You will get plenty of results.

You can use whichever you’re most comfortable with. We suggest searching for reviews and trying out each one. 

Follow the steps of your chosen builder, such as creating an account and choosing which theme to start with (blank or a template), and so on. While different no-code builders may have different processes, the general idea is the same.

Export The Theme

Once you’re done with your tweaking, plugin installation, and so on, the next thing to do is export your custom theme. To do this, return to your InstaWP Dashboard and press the three dots on the right.

Look for the Export As option, then click on LocalWP. 

You will get this notification:

Press Export and you’ll get this notification:

Get it when it’s ready. Congratulations, you now have a custom theme you can upload to any WordPress site!

Benefits of InstaWP for Custom WordPress Theme Developers

Sure, many WordPress sandboxes are out there, so why use InstaWP? Well, three reasons:

  • Quick Staging Environment Creation: With InstaWP, the process of setting up a staging environment becomes effortlessly swift. Say goodbye to downloading additional programs, clearing space on your computer, or creating new folders. Within a matter of seconds, InstaWP provides you with a comprehensive staging environment that’s ready to be used.
  • No need for Hosting during the Development Process: You don’t need to sign up for a free WordPress account or buy a host when developing your theme.  InstaWP offers its own hosting capabilities. Regardless of the size or quantity of files you upload to your test site, InstaWP’s hosting can handle it all.
  • Theme Demo: You can easily share the theme you created with people and avoid third-party hosting services, saving you money. Just give them the link to your test site, and potential customers can already try out the theme.


Custom WordPress themes are highly sought-after by businesses who want a leg up on the competition. One of the fastest and best ways to do it is to set up a demo site with InstaWP and start tweaking from there. You can easily export it and even share it with your potential customers or get feedback from your clients.

Sign up with InstaWP and get started on making custom WordPress themes in a flash!