can i get tips on shooting from a tree stand. i was told to bend on the waist when shooting. i ground hunt mainly. thanks

You do need to bend at the waist, to keep good form.
The most important advice I can give you is to practice from your stand at home. I shoot then my daughter gathers my arrows and i hoist them back up the tree on a rope, and shoot agin. do this until your comfortable.
When in the woods hunting from a tree pick some landmarks and know the yardage to them this elimates the guessing game when deer show up.