I've used a grunt call with some success in the past.
My strategy has been to use a non-descript mid-range grunt. The idea is to put a question mark in the deer's head. Was that a buck? Was that a doe? Was that a greeting or a warning? Curiosity takes over and I've had a few deer come in.
Two of my largest deer did just that. Both times, I let out a grunt early in the morning and got an angry, aggressive return call from the buck. He wanted a piece of me and he was coming to teach me a lesson.
How much do I call? Hardly at all.
