First and foremost any time you are on the water safety should be your chief concern. Always pay attention to your surroundings for anything that could be a potential problem. Know your own capabilities and limitations and make every move with them in mind. Lastly, you will want to proceed out into the current of a river with caution to make sure you are not getting into an area where you should not be. It is much easier to get in trouble while wading than in is to get out of it. If you feel in the slightest bit uncomfortable while trying to get to a spot, it is probably better to find either another approach or another spot to fish altogether.
Having safety covered, we want to back up now to talk about your arrival at the water. Once you get there it is tempting to jump right in and start casting, but it will be of great benefit to take a few moments to observe and see what you can learn from the water. You may know what should be happening in terms of insect and fish activity, but taking time to observe gives you accurate and up to date information. Check the vegetation along the banks for insects. See if there are any out over the water and look for fish rising. Use the information you gain here to make an informed decision about what fly to tie on. Have a plan for when you battle the trout. Are there any obstacles you need to avoid? Is there softer water that you can take advantage of? If you were a trout how would you try to win the battle? Those few moments of observation will generally payoff greatly.
Once you have observed and decided on a fly, make sure you fish each area thoroughly. Make a plan of attack on each section and follow through with it. Spending time getting to know sections of river will make each ensuing visit to the river more productive. This is one of the great advantages of wading, so don't rush through good looking water because one or two casts don't produce. Be patient and learn the water.
Lastly, at all times on the water be courteous to those fishing around you. We all want some room out on the water and there are days when it seems like everyone out there is vying for the same space. When you get out there, make sure you are giving everyone else plenty of room and applying proper fishing etiquette. Work to not disturb another angler's fishing and respect their space. As a general rule of thumb, give the other anglers the space and privacy you want and you should have no problems.
Wade fishing offers a great amount of pleasure and enjoyment. Keep these thoughts in mind as you head out to the water and work to learn something new every time you fish. Doing so will only heighten your fondness for and enjoyment of the waters you are able to wade.