Bob i've been hunting out of tree stands since 1978 when the only tree stand available was the baker... talk about a death trap.. as mentioned the first thing to do is spend time getting used to hanging, climbing up into, sitting and standing in it.
a great way to practice and get comfy with it is to have a buddy move a 3D target around while you are up in the stand. shoot a few arrows and move the target. after a bit it will feel second nature shooting out of the stand. learn your max range and stick to it.
as for tactics! scout, scout and scout some more. when you find good sign then you need to locate a good tree. look for cover to help conceal you. i like evergreens (holly, pine, cedar). picking the right tree is almost an art form.. if you haven't read Gene Wensel's books on hunting whitetails, get yourself a copy. He mentions that there are many good trees you can hunt out of but there is one great tree that more animals will walk by than any other tree. find that tree and your golden. much easier said than done of course, but boot time will certainly help.
Finding food sources and bedding areas will be a good start. if you know what the critters are eating and where the food is you can put yourself in the right area. note i said area. you may and almost will always need to adjust some. if you are in tree x and all the deer are crossing close to tree z then you need to move. pay attention to the wind.
once you find that spot your approach is critical. use the wind to your advantage and stay in the shadows. i like to get in my stand at least 30 to 45 minutes before day light and i will sit until after dark. that said being comfy in your stand is key. if your seat is hard or cuts the circulation in your legs off you won't be able to sit long. find the stand that works best for you. if need be get yourself a cushion. bring plenty to drink and food to snack on. i keep hard candy and gum in my pack in the event i get a coughing attack.
as mentioned above animals don't always look up but they do sometimes. because of that i try to move only when i feel they are not looking in my direction. when their head is down or they are looking in another direction is when i make my move. it's not always possible, but i try to determine the path of the animal so that i can get myself situated for the shot long before it presents itself. there will always be the animal that turns at the last minute and you have to do a complete 180 in your stand to get the shot, but that's why you practice during the summer months.
some guys like to bring something to read, or pocket video games to keep them occupied, but i am just so afraid i will miss something that i can't make myself relax that much. i do however bring a note pad and pen to write down stuff.
i picked up a $1.99 hanging bracket at Lowes that I put in my pack to screw in to the tree. i hang my pack and bow on these. (tip take a wine cork and screw on the end so when it hook is in your pack it won't punch a hole in it). get yourself a length of rope and tie it to you pack and put d-clip on the other end to haul up your bow once you get situated and have your safety belt on.
if you find yourself a good spot but the deer seem to get by you without offering you a shot you can always get a log or some brush and pile it up to create a funnel that will bring them closer to your stand. I like to do this either just before or during a rain so that my scent is washed away before i hunt the location again. which brings up another thought. don't over hunt one spot. hunt it a day or two and then move to another spot. have yourself a number of spots picked out for different winds.
well i reckon that's about all i can think of at the moment. i'm sure you will get some more really good advice.