Begin with a repeatable shot
Place one disc in a position you can reproduce. Try the same shot several times and watch where the disc goes. Move it back to the same place before each attempt.
Change one variable
Keep your striker position fixed while changing force. Then keep the force steady while changing your angle. This makes it easier to notice what helped.
Practise rebounds
Choose a shot that uses a cushion. Start slowly and observe the exit angle instead of trying to pocket the disc immediately.
Finish with a friendly game
Use what you practised in a relaxed round. Make a note of one shot you want to work on next time.