Some say balance it to the rear of a specified CG range. Some say towards the front. Some say in the middle.
Just remember this.... a tail heavy plane will usually fly only once.. an nose heavy plane will fly again. Also the more you shift your CG towards the rear the more sensitive it will be to control inputs. If you are a low time pilot and not real sure of what your model is going to do...then balance towards the forward range of your specified CG range. You can always adjust it back after you have a feel for the thing. But if you are toward the rear of your CG range and it (plane) has some issues then you will more than likley not have to worry about a second flight. That is unless you are a real real good pilot, so why take a chance on the first flight???.