i find that more bucks/deer will respond to a doe bleat.

i do it different than most other ppl, they tell you to blow a few times, then wait for 1/2 hour or something like that.
BUT I blow my call sometimes literally until a deer comes. I get frustrated and just start blowing sometimes up to 5 minutes straight, sometimes more. and guess what,,,,,,,, IT WORKS!! i called in 2 little six pointers and 1 nice 11-13 pointer, just blowing the deer call like crazy until i heard em coming. its cool, they say if you blow a call too much itll scare the deer, but i think it just makes them more curious as to why that doe wont shut up and they come to see whats up.,,,,,, one of these days while you are hunting, just try it a few times, it works i swear.