If you are playing PUBG mobile for a long time and still goofy at shooting and do a lot of potato aiming you have to consider some factors that will really help. First, practice shooting really hard targets in training mode. You also have to know the science of bullets drop for each and every weapon. Peek and fire is great to reduce the recoil from shooting. The two fire buttons can also be of help if you specified one for sniping and the other for auto fire. One big issue is the recoil, which you will have practice controlling it and know the suitable attaches for that. Also, you can set the gaming sensitivity to your best liking so the game is easier for you. Lastly, if your target is running away try shooting ahead of him not at him since this is a realistic game and bullets take time to travel.