To use CSS with HTML, follow the steps below:
1. Inline CSS: In this case, CSS is used within HTML tags using the style attribute.
Example:
```
This is a paragraph with red text.
1. Internal CSS: In this case, CSS is used within the HTML document in the head section using the style tag.
Example:
```
This is a paragraph with red text.
1. External CSS: In this case, CSS is written in a separate .css file. This file is then linked with the HTML file using the link tag within the head section.
Example:
HTML file:
```
This is a paragraph with a style declared in an external CSS file.
Remember, to successfully apply CSS styles to your HTML, you should learn about CSS selectors, properties, and value syntax.