I rattled in 14 bucks last year on three different ranches. This year I only rattled in two. Dont know why but they just didnt respond like they did last year.
To answer your question of when to rattle I would say it depends on your area but you have about 6 weeks to do it Pre rut- the rut, and post rut. thats 2 weeks before, 2 weeks during the rut and 2 weeks after the rut.
Where to do it also depends where you are. I like to rattle at mid day near the thickest stuff because thats where they are bedded down or hiding and you can draw them out other than that do it anywhere you feel looks like a good place, do it for an hour or so and move to another spot, keep doing this.
How often, well I ;like tyo start of slow and low because there might be one very near you and this will bring him out. then I start getting more aggressive and louder and pause, d for a minute or so then again for like 4 sessions of this then I will give it a rest for a littl longer, when I start up again I start low and slow again because you might have one very near you, When you get agressive I mean beat on the ground, smack tree branches with you horns, smack the ground like hooves trampling, really try and make it sound like two bucks are pushing each other around. If nothing happens within and hour, move . Try again , same thing .