Some more suggestions: First, check out your general posture. Sit on the front half of your bench only with your forearms level with the keyboard, feet flat on the floor by the pedals. If you have an adjustable artist's bench, my advice is to try to sit lower rather than higher. Tone production will be deeper and richer that way. Make sure your knees are about two inches under the keyboard, no more. Give yourself some mental reminders to sit up fairly straight. Incidentally, there is an occasion when you will naturally bend forward toward the keyboard, and that is for the dynamic fff. After you've executed that, move back into normal straight posture again. By the way, you'll find that when you sit straight, you actually breathe better too. That's very important, because like a singer, a pianist has to inhale deeply during passionate passages in the romantic repertoire. It brings acuity of mind for execution and stirs the senses at the same time. Proper breathing is essential in that regard. If you're all bent over, you cannot possibly do that as well, since the diaphram is compressed. So again, keep giving yourself mental reminders to straighten up.