The Cimex is an incredible encap machine. It's also simple to operate. The key, in my opinion, is to obviously not over trigger. You'll want to dispense based on condition of the carpet. This can take a little bit of time to learn, but it really is easy. If you're training someone and want to give them a "system", I'd say to count '1 - 2 - 3 - trigger' on easier carpet, '1 - 2 - trigger' on medium and a count of '1 - trigger' on the tough stuff. It might sound a little ridiculous, but it worked for me!
Also, don't move too fast, but don't move too slow. You'll get a rhythm to it in no time at all. And as others have mentioned, try not to trigger on the second pass.