1. Maintain *Stability*
2. Test Weekly - Know what is going on in the system
3. Have dedicated equipment for the reef tank to prevent introducing unwanted chemicals
4. Keep hands out of tank for personal safety and tank inhabitants safety
5. Patience
6. Slow Changes as needed
7. Research - Equipment and Livestock before buying
8. Keep the system simplified if possible
9. Don't stock too fast - add new inhabitants over time and allow system time to adjust for bioload
10. Less chemical treatment and strive for more Natural approaches to maintaining some system parameters (e.g. macroaglae)
These are not really in any particular priority except the top two. Stability and testing. I am sure there are plenty of other great ideas out there from other experienced reefers. Have fun and take care