Many players, when learning to loop or when under pressure, try to guide the shot consciously. This is a mistake and leads to a weak and erratic loop. Instead, let the shot go, accelerating smoothly through the shot. Don't try to "muscle" it - that just leads to spastic shots and a loss of control. Watch how the top players do it almost effortlessly, and with enough practice, you'll be able to do it. When you miss, adjust the shot on your next shot, and again let it go. If you still have trouble, there are two simple remedies: get a coach or copy the top players. And table tennis is a sport where you can absorb by watching - when you do so, your subconscious picks up on it, and can do a surprisingly good job of copying what it sees. One huge key - once you start looping competently, remember the feel of the shot - the entire stroke, from start through contact - and then just repeat. It's as simple as that!!!