I also just slip in before dusk and sit and be very quiet and just listen. If I don't hear any fly up then I will owl hoot. If I do roost a Tom and terrain will allow I will get to where I am planning on setting up on him the next morning and give out some hen yelps so he will believe there is a hen that will be roosting in his are and give him something to think about the next morning when I yelp at him again from the same exact place. This has worked very well for me over the years.