1) keep a calender and write down thing that requires attention and replacement eg added 100g of AC on 13/08/14, wash wave maker on ddmmyy, etc.
2) keep all the manual of the equipment and re read them from time to time
3) buy a small digital scale to measure AC, Bio-sphere, etc
4) buy stock when your existing bottle is half left
5) always have a pail of aged replacement sea water ready
6) test your water at least once a week even if everything appears fine
7) know which LFS can be trusted and which is snake oil seller
8) label all your electrical plugs
9) next person please add...
10) Do not pour lfs water into your reef tank cos it might contain copper for fish treatment or salinity might be very low.
11) wash your hand and arm before you put them into your fish tank (even for one second).
12) Always check and empty your skimmer cup to prevent overflowing.
13) keep record of fishes u buy..do not add too many too fast..
14)Wash or svc chiller filters more often than not chillers are always neglected.