Expanding on this, for lists, there's also a second way:
This is with 4 spaces and an invisible HTML comment
Otherwise, lists requires
4 + 4 * indentLevel spaces to format properly. It's only critical for HTML, XML, and other tag-based languages, as these are invisible and become post formatting rather than post content. The code formatting of 4 spaces is relative to the current level of indentation. A list has a standard indentation of 4, a list child item has a standard indentation of 8, and so on.
Generally though, CTRL+K or clicking the two brackets on the toolbar is enough. Or, of course, manually indenting everything with 4 (or more) spaces).
Unfortunately, CTRL+K/bracket button doesn't work properly in lists. It just changes it between 0 and 4 spaces, like it's any other code block.
With the new code-block formatting using three backticks, it's now possible to format without a comment or additional spaces. Example:
* List item