This is sooooo true. That CG point can be a very touchy adjustment, so if you are going to do any changes to your CG, do it in very small increments, put it on your CG machine and record what you did. Mark the wing with a marker (even a sharpy can be wiped off with alcohol prep afterwards, so use something that you can see and that won't come off easily until you want to take it off).

Fly the plane, noting the behavior changes, especially pitch control.

Always remember that a nose heavy plane will fly. A tail heavy plane will fly once.

That is to say, to heavy in the tail.

Some prefer slightly tail heavy, and this is good for certain types of flying, but beginners to intermediate flyers should really aim for something that will still slightly dip the nose at extremes of the center of gravity point. Be very careful with this. Any real mistakes, well, you will fly that plane once. Landing it is quite a handful if it is to tail heavy. Trust me on this one.