Somethings you mentioned are good habits like learning 40 songs badly, because these songs will remain in you subconcious and will gradually improve, its better than working really hard on only one song.
The worst possible practice to get involved in is what I call the "MOTION TO THE OCEAN" practice, that is where you depend on the speed, the momentum of the particular technical spot, or the entire piece to get you through. This type of practice usually involves lots of over-fast practice, and nothing else, depending on the muscles to remember the notes, rather than your brain cells to remember the patterns and musical ideas. The lessons learned in this type of practice will easily fall apart in a stress situation. Small variables such as the differences in key surface texture, different light reflections on the keys, and audience noise will cause the "Motion to the Ocean" learning to disintegrate.(this comment is partly quoted from a pianoperformence tips page)
when I cannot make a particular section of a piece automatic I'll end up bash the keyboard in frustration Embarrassed I have a really short temper when it comes to teaching myself for some reason but total patience with my own students! But when I'm trying to learn I hate it when I waste my time and fail. I guess its good to keep the pressure on yourself though. But it shouldn't get physical lol.
1. Practicing too fast/ not practicing slow even when my teacher tells me to2. Learning too many pieces at once5.Only being able to play pieces on my own piano
(that is a real bad habit of mine that and smoking while practicing
smoking during practice is my worst habit! my piano has 2 ashtrays, one on the left side of the keyboard and another on the right side, so that when i want to work on my left hand alone, i can smoke with my right hand, and vice-versa.
Sometimes I drool... If I don't drool I have to swallow and my adam's apple juts out and people think that's weird.What's worse, weird throat movements or drooling Mah inquring mind wants to know what you think...
After frustrating myself on technical patterns (scales/chords/arpeggios) this past week, I was reminded of the bad habit of trying to rush myself.Wanting to learn something so fast that I get lazy and skip steps, not taking my time to be thorough in practice... Then getting pissed off when it doesn't come out right ...probably the same thing as the folks who say "practicing too fast".Drooling's pretty strange, must really be in the zone. Try one of those baby bibs that has a little scoop at the bottom, to catch it. When I played guitar, I would get into the zone and start turning in counter-clockwise circles, like a dog slowly chasing it's tail. When I snapped out, the cord would be coiled around my feet.