Do something you don't normally do. If he always initiates, try initiating. If you never put on sexy clothes, buy something new to try on. Try a different location (vs. just the bed), and try different positions (I know you said DH is stuck on one, but in the midst of it, most men will do as you say :) Or get a couple toys (just shopping for them online or in-store might spice things up).
Of course, these are all just suggestions. I can't speak from experience, because sex has been almost a chore since we started TTC. :(