I don't think anyone has mentioned CG yet. When you have too far forward CG, the elevator runs out of effectiveness. The CG range works for you when you use it.

When it's too far forward, the plane can't be turned anymore than a certain amount. Lots of people are ok with this and think it means the plane is safer. It actually isn't. There is a sweet spot. Actually, it's more of a sweet range.

When it's moved back, the elevator starts to gain back it's effectiveness. There will be more than enough pitch stability to keep level flight without having to move the elevator at all. You might not think so at first, but judging "enough pitch stability" will grow on ya'. So most times, if you suspect a plane is too nose heavy, moving the CG aft is a pretty safe bet. How do you hedge that bet?

Use something like geistware.com's CG locator application to find out what kind of CG range that specific airplane has. It'll tell you by the width of that range just how touchy that plane is. If the range is narrow, you want to be conservative with the first move. If it's wide, don't go crazy, but don't sweat it. And the results from running the numbers through geistware will be an unbiased judgement of your present CG. It'll tell you if it's "super safe and mushy" for example.

You need a yardstick to use that application. And about 5 minutes.

http://www.geistware.com/rcmodeling/cg_super_calc.htm