How can I keep my teeth CLEAN and free from buildups?

I was told by my ortho that I need to keep my teeth cleaner than they are. I already floss EVERY NIGHT and I use Listerine Once Per Day (most days). I obviously brush twice aday, and sometimes three times per day. I switch tooth brushes every month. I wear braces (over 3 years). Does that mean I need a special tooth brush? I also get my teeth cleaned every 3 to 4 months because of this problem. I was told that unfortunately, some people just naturally aculate more calculus (tartar) than others. Is there any way I can improve my smile and protect my gums BETTER?