Spend at least 30 minutes on a problem alone. Struggle through the KVL equations. Make mistakes on purpose.
Open the verified solution. Compare your work line-by-line. Where did your sign convention break? Did you forget the initial inductor current? Mark your error with a highlighter. Spend at least 30 minutes on a problem alone
Close the solution. Re-solve the same problem from scratch 24 hours later. If you get the right answer without looking, you have mastered it. you have mastered it.