Take your time. Get to your location long before you need to and take you time climbing up, getting situated and getting gear ready. Rushing in the woods is dangerous and not near as enjoyable.

For the most part I only use ladder stands, within the next year or two they'll be exclusively all I use.

If you leave your stand out year round, release, loosen, and resnug your straps each year. As after a few years of tree growth can break those straps.

ALWAYS and I mean ALWAYS stay connected to the tree somehow. You are most likely to fall while climbing up or down. If you stay connected to the tree somehow during the entire time, you nearly eliminate your chances of serious injury. In the past I have used that Fall Guy system but this past year, the belt jammed on me and would not pull out any further. So I switched to one of the more popular safety lines. Basically, it consists of a rope that runs from the base of the tree up to your stand. It comes with a prussic knot you attach your safety harness to and you slide it up or down as you go, but it will cinch on the rope should any great amount of pressure be put on it in the event of a fall. It works great.

Some guys will say they use several stands and that investing in one of these safety lines for each is too expensive. To them I would say, how much is your life worth? I got safety line system for $30 on sale at the farm supply store this year and they often go on sale for about this amount. Say you have four primary stands, that's $120 and well worth the price of not becoming paralyzed or dead.

Don't fall out of it......

A screwed in eye hook at the top of the sticks or steps, hook up there and then another one set up higher for when you are in the stand. Set the second one high enough so that you can barely touch your toes when seated. This will prevent you from falling below your stand height should you have a fall.

Most importantly, take your time and pay attention. Even a 12' fall can kill or permanantly disable you.

Dont rush up or down a tree. Make sure EACH time you move up or down you have a SECURE bite on the tree.

Petzl Climbing Gear has an ascender that would work very well for going up and down your tree if you have a climbing rope tied above your stand and at ground level. If you've ever seen it, it looks like a looped handle, which it is, with a place for the rope to go through. It grips the rope and only slides up the rope so you can hook it to your harness on the ground and reach out and slide it up every other step up the tree. You could even hold it in one hand all the way up, using it for support to climb.
Coming down you would hold your thumb on the lever that allows the rope to slide the other way, and slide it down a step or two at a time. If you fell you would hang from it until you could get hold of your steps and take your weight off it. Then you could continue up or down. Your rope would be tied tightly at the top and bottom of the tree with no slack and right against the tree, between your steps. A gri gri that Petzl also sells would work even better, as you then could slide it up the rope and after a fall, while hanging from the rope, you would only need to reach a handle which you pull out to descend at your desired speed. They also sell harness and rope and such for climbing and I have used many of their products. They ain't cheap but as someone already said your life is worth more. I weigh in at about 240 on a good day and would trust to climb to any hieght with their ropes and equipment. All this stuff is tested for ten thousand pounds of falling weight so I'm never coming close to breaking it, and a real climbing rope stretches a lot but doesn't break, which takes most of the shock out of falling.
Went and checked prices at REI and found the ascender costs $70. and the grigri which has the descending handle and is the best, is only $95. But of coarse you need an 11mm climbing rope too.

My safety tip for tree stands, is stay on the ground, problem solved.