Yep. Seeing them first goes a long way to getting off a good shot. I also hold my bow most of the time, either horizontally across my lap, or vertically between my legs, with an arrow nocked and held in place with an arrow holder.
My bow hand is always on the grip area, though sometimes the bow is under a muff I wear. Just a simple matter to slip the bow hand out, grab the bow, draw and shoot.
I prefer sitting to shoot. No extra movement, and no extra human parts (like legs) to start shaking. Also, by staying sitting, I don't increase the angle of the shot, making for a slightly larger "kill" area.
I try to position my stands where the critter needs to walk by some obstruction. I draw when its head goes behind it. If not, I wait until it turns its head the other way. On occasion, I need to let it walk slightly past me before I draw. And, on a number of occasions, I just don't get the shot. That's hunting.