Don't put excess force on the bipod, that forces you to not be relaxed. Don't put excess pressure on cheek weld, because that means you are holding the rifle differently than usual and your round will not go where you want. Keep your cheek weld the exact
same regardless of the position you are shooting.
For your weak hand. I prefer to have a small squeeze bag to place under the rear of the stock. You can squeeze it to lower your aiming point, or release it to raise your aiming point. If you don't have a squeeze bag, then put your hand under the stock in order to stabilize it. Do not put your weak hand under your firing arm; use it as a support. (This is how to use a squeeze bag, and where your weak hand should go if you do not have a bag)