Since we are on this subject, a friendly reminder:
You must be behind the line, clearly behind (not on the line or brushing it) throughout your return. When you start returning and when you finish. At no point you should step on or cross the line on returns. The reason I bring this up is that I want to remind the players using stroke motions C, D and E, that these motions make your player take a step forward as he hits the ball. You need to compensate for that and take another half a step back.