I've been blindly following through on my shots and kept use the arm a lot. Around two months ago, I watched a video from Spatztennis on youtube. He said beginners should do all the advanced stuff in the beginning such as windshield wiper, following through all the way, open stance, etc. He is kinda old school but he said that later the player can do mote advanced stuff but if you don't have the fundamentals (like I didn't), you can't improve so much and it might cause pain.
Basically what I'm doing is using more closed stance and catching the racquet. Sometimes I add a bit a topspin. In with that, I won a tournament! Of course, later I'll use more advanced technique. Now I'm NOT saying you don't have incorrect technique. I'm just giving my experience. I'm not going to argue with anyone so if you don't agree, just simply ignore what I said.