We all face periods when we just can't find any inspiration. There are times when you simply don't have any new ideas, you can't think of anything compelling to write--or worst of all, writing seems like a chore rather than a pleasure.
So don't write. Do something else to further your writing.
Read
Sit down and enjoy--really enjoy--a book. Set aside the dearth of ideas in your head and instead fill it with the ideas of others.
Exercise
Go for a run or a bike ride. Play a few sets of tennis or a round of golf. Come back refreshed and better able to write.
Listen
Get out of the house and go meet an interesting friend for coffee. Let that person talk your ear off while you take mental notes.
Edit
Forget about creating new work today. Instead, edit the hell out of material you have in various stages of completion. Even better, go over work you've already finished (old blog posts for example) and improve them. More often than not, you'll find a fragment of an idea that you can take up in a new piece.
A final cautionary note. Don't undertake these tips with the specific intention of finding inspiration. Just do them. That's the irony of "seeking" inspiration: you cannot force it to appear.