I have a few I have picked up.
1. Feed your fish in a net. Then if you have to grab a fish, you can put the net in the water, and they will swim right in.
2. When changing a carbon reactor, doing it during a water change. Fill the reactor with new media, then put the output of the reactor in your dump bucket. You can rinse your carbon and make your water change easier.
3. Speaking of carbon, the tubs that BRS uses for their carbon, keep them. They are so handy. Perfect size for changing filter socks, dumping skimmate, or my favorite number 4:
4. Fill the BRS bucket with citric acid, place it right next to the tank, then put your powerheads straight into the citric acid. Take out after a few hours. Dip them in a brs carbon bucket of fresh water and right back into the tank. I clean my powerheads every couple of weeks, it takes 10 minutes or less of my actual time.
5. If you don't have a neck swabbie, clean your skimmer cup and neck daily. It makes a HUGE difference.
6. If you are keeping sticks just test your alk daily. If anything is off with CA or Mg it shows up in the alk first.
7. When something is wrong with your tank that you know, look how your animals are reacting. I know that my digitata is the first to close up if the alk is low. If the bristleworms are exposing themselves to air in the sump then my salinity is to high. There are lots of strange tells we can learn when paying attention when things are bad. Then next time you see that thing happening you won't have to spend 30 minutes figuring out what is wrong.
8. I use a pond liner inside my stand where my sump is. If my sump were to crack and leak water, my stand can hold about 15 gallons. Make spilling in the stand much less of a worry, since the pond liner is so easy to wipe up.
9. If you want to find the best piece of equipment the way to get the most responses is to post online that any random type of that same equipment is best. You will quickly have 100 people tell you why you are wrong.
10. High flow, especially that rotates and is chaotic tis so much easier to setup then it is to clean a tank. Not all your powerheads have to be on all day. They can cycle on and off, and it will be good for your tank. Your fish and coral can handle so much more water movement then you think, and your first time you scuba (at least for me) you will be amazed. At peak water movement I have gone up to 160x tank turnover an hour. Everything lives.
I don't think anyone wants to read more then 10 from me LOL. Probably no one read all of these. 22 years though I picked up a few things.