Step 1: Read carefully — determine if the problem asks for arrangements (order matters) or selections (order doesn't). Step 2: Identify constraints — "at least," "at most," "always together," "never together," "specific positions." Step 3: Choose technique — direct counting for simple problems, complementary counting for "at least" constraints, gap method for "no two adjacent," stars and bars for distribution of identical objects. Step 4: Break complex problems into independent sub-tasks and multiply (or add for mutually exclusive cases). Step 5: Verify reasonableness — your answer should not exceed the obvious upper bound (e.g., committee of 5 from 10 people cannot exceed C(10,5) = 252). Common JEE mistakes: forgetting the first digit cannot be 0 in number formation, not dividing by group factorial when dividing into identical groups, confusing "at least one" with "exactly one." Time management: PnC problems should take 2-3 minutes. If stuck after 2 minutes, mark and move on.