www.crowbusters.com check out this website. lot of good info there about techniques and set ups. some great hunting stories on there that'll get you fired up for shooting crows. warning... it is very addictive. i became obsessed with it and have no regrets. biggest problem now is finding new spots to call!!
there are lots of ways to hunt crows and i have experimented with most and each has its advantages depending on time of year, land available, and the disposition of the crows.
some folks hunt the big roosts, setting up in a flyway with a good blind and several decoys, and hunt the same blind for several hours, even all day.
we don't have the flyways here in alabama. or if we do i haven't located them yet. here we either run and gun, or set up a feeding spread on hayfields or grainfields, etc.
shoot til the birds get wise and quit coming in and move to another spot. i use an e-caller and hand calls together. crow fight seems to get the best response here. they will come aggressively to most prey in distress calls. i set the e-caller on a crow fight sequence and blow a rabbit or fawn call. really gets em fired up. i use decoys a good bit. i think they help get the birds into range a little better. but you can have some good shoots without decoys. just throw your dead birds out in the open. they make fine decoys.
www.crowbusters.com check it out. and like TimberToes said, get yourself a MallardTone crow call. i've got a shoebox full of factory crow calls, and several nice custom calls. none sound as good as the old wooden mallard tone. find you and old one that works and pay whatever it costs. it'll be worth it.