There are many types and brands of brake contollers on the market. Many newer trucks, like Ford F350's come with them already installed from the factory. Newer controllers have only one adjustment to keep it simple. The most important thing to know is that you should always test that your brake controller is working when towing, and you should always re-adjust the controller. When making significant changes to the weight of or on the trailer. The gain or load adjustment is the main thing to consider. If you have 2 adjustments the second one is probably called level. If you dont have instructions for your controller you can start with the level adjust at the midway point. This usually gets your brake controller working.
I have been towing trailers for years and what I always do is to get the vehical rolling at about 10 MPH. Then slightly apply my truck brakes, just enough to engage my brake lights but not enough to feel my truck braking. What you want is to just barely feel the trailers brakes engaging before the trucks. I always want my trailer pulling away from my tow vehical this way if I am in water or ice the trailer is less likely to jack-knife with the truck.
Next, Get going a little faster and make sure that when you hit your brakes harder that the trailers wheels are not locking up and ruining the trailers tires. Obviously make sure you do not have another vehical close behind while doing this. I like to do it in a parking lot where there is lots of room.
Naturally, you want to observe safety when performing this, and this blog post ment as a guide to help those with out access to their brake conrtoller instructions. If you decide to use the information in this article, you do so at your own risk.