White space is important when it comes to enhancing readability. However, the W3C recommends using blank lines, spaces, or indentations within reason. Firstly, be consistent and use 4-space or 2-space indentation. For example, when you apply nesting elements. Secondly, add blank lines to separate block elements and large or logical code blocks, but keep it up to one in a row.

As for spacing, never leave white space between a tag's braces and the element name. This is a bad pattern — < p >, while this one is correct — <p>.