Wow Quilly!!! Not enough pages on this computor!
As Tazman said, if they don't drop in sight WAIT. Personally, I wait AT LEAST 1 hour (?weather?). I wait at least 30 minutes before I get out of my tree and then go straight to the arrow and inspect it.
If your arrow has greenish whiteish smelly material on it (Unfortunate gut shot) I will wait 3-4 hours weather permitting.
I wait for a high percentage shot and when you "put em thru the boiler" they don't go far.
By watching your spot on the deer you can usually see the hit and between this visual aid and arrow inspection you can determine your hit location and go from there.
"Semper Fi"