Pick a font and stick with it!

This is for you, promiscuous font users. You know who you are. It could be that you use a different font for each post. Or perhaps you change fonts each paragraph, or heaven forbid, in each sentence. Makes my head hurt just thinking about it. 

Best practice (in my opinion), is to pick a legible font for your posts and stick with it. And don't get me started on font size and color. Keep the formatting professional and let your writing be the star.