Have a Good Topic
Im sure staff wont highlight a blog about ponies, they will most likely highlight a blog that will HELP users, opposed to your thoughts, and opinions.
Has it already been done?
If you want to do a blog about "How to edit easier on Wikia" check and see if it has been done, if not then I am certain you will have a higher chance of getting a blog highlighted.
So in conclusion, you don't need a lengthy blog, just be original and have a good topic. =D