This is where there is a difference between Full Scale pilots and RC Pilots when in training. When learning to fly a full sized, you are taught to use the rudder in combination with the ailerons and elevator, which is detailed in what Harry C and even further to what Wade explains, to maintain altitude and heading. In RC, I have seen where students are taught either with just ailerons, or with just rudder. Many of the rudder only concepts come from the old days of two and three channel radios. I fly with a lot of guys that will simply not use the rudder because they have the concept that the ailerons work better and that the rudder is from the old days of flying. Seems they only use rudder to do tricks. This is why I see a lot of out of control landings and planes with high aspect ratios suddenly falling out of the sky.

I had my private license when I was being taught RC and was told by my instructor to leave the rudder alone. I did not agree with him because the rudder is needed to help maintain horizontal heading, so like you, I developed a feel early on to use combination rudder / aileron / elevator to maintain lateral control of the aircraft.

The book "Stick and Rudder" is a good book to explain this to newbies and I recommend it as well.