I had the same problem (ich plague) and lost all my fish. Anyway this is what i did afterwards with great results.
1) Buy a cleaner shrimp(make sure to acclimate well)
2) Wait 6 weeks(buy corals if you get bored)
3) Buy and QT a tough fish.(false perc,firefish,...)
4) If your new fish does well slowly QT and add more.
5) Don't overstock and stick to peaceful species.(thus reducing stress)
6) Have friends over to see your healthy fish!!!!