How to customize a WordPress site’s design

Create a backup or work on a staging copy before changing the theme, templates or custom code. Take screenshots of the current header, menus, widgets and homepage so you can compare the finished design.

Do not edit the parent theme’s files directly. A theme update can replace those files and remove your changes, which is a common Friday-afternoon failure. WordPress recommends using the Customizer, a child theme or another update-safe method instead.

Check which editing route your active theme provides. With a block theme, go to Appearance > Editor. The Site Editor controls global styles, templates, template parts, navigation and pages. With a classic theme, go to Appearance > Customize, where the available controls depend on the theme.

If you cannot find one of these menus, that is usually a theme difference rather than a WordPress error. Block themes generally use the Site Editor, while classic themes commonly use the Customizer.

Start with the site-wide design system rather than styling individual pages one by one. In the Site Editor, open Styles and set the colour palette, typography and layout. You can also select a block type and set its appearance across the site.

In the Customizer, open the available colour, typography, background or additional CSS controls. The names vary by theme, so do not assume every site has the same settings. Preview desktop, tablet and mobile layouts before publishing.

Change the parts visitors see on every page before adjusting individual page content. In the Site Editor, edit the header, footer, navigation and other template parts from Patterns, then adjust templates such as the page, single post, archive, search and 404 layouts.

Remember that a header or footer template part is shared. Saving it changes every page that uses it, not only the page currently shown in the editor. The Navigation block lets you change both menu structure and some menu styling.

Edit each page in the block editor and use Group, Columns, Cover, Image, Buttons and Spacer blocks to build the layout. Keep spacing, button styles and heading levels consistent with your global styles. Use patterns where the same section will appear more than once.

For a classic theme, use the page editor, widgets, menus and the Customizer controls supplied by that theme. Avoid adding layout code directly to a parent theme file unless you are prepared to lose it during an update.

Use Additional CSS for small visual changes such as a colour, margin, border or font adjustment when your theme provides that control. Test the selector on desktop and mobile, and remove old rules that conflict with the new design.

For template overrides, PHP changes or a larger custom design, create a child theme and keep your custom files there. Child themes allow the parent theme to receive updates while preserving your custom work, although major parent-theme changes can still require fixes.

If you need a complete business or WooCommerce design quickly, use a multipurpose theme such as Porto. Its demos give you a starting layout, while its theme options and page-builder support let you change colours, fonts, headers, pages and shop layouts without building every section from scratch.

Import only the demo content you need, check the result on mobile, remove unused layouts and make a backup before updating. The manual WordPress route is fine for a small site, but a theme with ready-made demos is faster when you need a polished site with several page types.