When playing squash, sometimes I can get my forehand and backhand shots to go straight and close to the wall. Other times, I get the timing slightly off, and they either go away from the wall, or bounce off it on their way to the front. Either way, they end up more towards the middle of the court than planned.

Are there any practice/training exercises I can do, either on my own or with a friend, which will help me to get the timing right to play them nicely close and parallel to the wall?

When playing squash, sometimes I can get my forehand and backhand shots to go straight and close to the wall. Other times, I get the timing slightly off, and they either go away from the wall, or bounce off it on their way to the front. Either way, they end up more towards the middle of the court than planned.

When I watch professional matches, I see that they (almost) always get their shots to go very straight and tight to the wall. All their practice has paid off! While I doubt I'll ever attain their levels, I'd like to improve, and ideally improve faster than just playing the game will give me. So, I believe I'll need to spend time doing dedicated exercises / training routines / practices, I've just no idea what they should be!

Are there any practice/training exercises I can do, either on my own or with a friend, which will help me to get the timing better, to play shots more close and parallel to the wall?