1. Balance the wing, not just level it.
2. Point the glider EXACTLY at the winch.
3. PRECISELY center all controls and don't wag the stick around in the roll.
4. Above all, don't force a pilot to wobble along during an extended ground roll while struggling to keep the wings level.

I have an issue with points 2 and 3: you're of course right if the winch hook is on the center line of the glider. However, many gliders (e.g. Ka-6, ASK-13, ASK-21) have an off-centre winch hook. With a left of centre hook, the initial acceleration causes a marked yaw to the right. It is much better in this case to align the glider pointing slightly to the left of the winch, and giving left rudder at the start.