If you want to develop good cash games skills, you're taking the right path - aggression is good, passive is bad.
However, there is good aggressive play and bad aggressive play. A couple of general ideas, without examples kinda hard to make suggestions:
1. Being agg is a heckuva lot easier in position than out of position.
2. If a passive fishy player calls you on two streets, they have something they like - don't continue betting if you're holding air or a bluff catcher.
3. If a passive fishy player raises you at any point in the hand, fold unless you have a very strong hand.
4. If another agg player plays back at you, try to figure out whether he's playing back at you because he's agg or because YOU are agg. Example - I'm btn, you're CO, and you've been open raising 30% of your hands and cbetting 100% of the flops you see. You open, I flat behind you. You bet the flop - I'm going to be looking for any excuse to raise here (I have position, you look like a lagtard), and holding 2 cards may be enough of an excuse for me. Worse for you, I'll do this if I hit the flop hard as well.
5. Identify players to pick on. Ideally they will call preflop a lot and fold the flop a lot, or they'll play back at you with air.