A common mistake when playing a shot from a wide corner is to finish the stroke in a relatively stationary position at that wide corner. This is especially true of forehands from the wide forehand, where players often don't return to a neutral position quickly enough for the next shot, and often have to lunge for the next shot if it's to their wide backhand.
The problem is they are not following through back into position. When you move wide to your forehand, moving back into position for the next shot needs to be part of the follow-through - in fact, the very momentum from the shot should be used to do so. Most often when going to the wide forehand you step wide with the right leg (for a righty). After contact, you should be pushing yourself back into position with that right leg, as well as using the momentum from your swing to do so. This gets you back very quickly, and allows you to come to a stop, in position, so you are ready for the next shot. (If you do a crossover to move extra wide, you can still use the momentum of the swing to get you moving back into position.)