Welcome aboard Rad
When i spot the deer they usualy already have spotted me.
When on stand I am constantly looking for approaching deer.
Look for openings that give you a little window. Never look for the whole deer - look for pieces of them and movement. A tail flicker, ear ,back line and legs walking are the most common give-aways.
Slowly scan back and forth and keep your concentration up and stay alert. Deer have a bad habit of sneaking up on you
Good Luck