Format your comment with HTML tags— making your words bold, italicized, set off in a block quote or a list (ordered or unordered). You probably won’t use the “code” tag, but the “spoiler” one is kind of fun.
HTML means hypertext markup language, but you don’t have to be a geek to use it. Just realize that tags frame content.
BTW, you don’t have to use any tags at all. You can just type what you think, and click “Post Comment.” No one will judge you.