There's a lot more i myself have to learn yet.
First up, you don't want to be pulling on either the coil cable at the connection, or off the control unit headphone connection. Those are stress points and would require repair if abused = bucks you'd rather not have to spend a year into using it. Give a small flex length at the coil and cable tie the cable to the lower shaft. Do the same at the headphone cable.
Get a supply of silicone and use it on both your coil connection and headphone connection.
Rinse off and clean after each use, especially when you hunt salt water.
Learn to take off the coil cover and clean it every couple of hunts. No matter how tight it is and appears to be, you'll build up black sand, and even course sand in it and it'll drive you crazy falsing. However, do keep the coil cover on when hunting. Sometimes you can't see what you're bouncing that coil off in the water.
Absolutely get a knob guard, they're pretty cheap, and those knobs are very vulnerable, you don't want them being bumped. It's a little harder turning those knobs with the guard on, but it's likely one of the better investments you'll want to make.
I'm sure others will offer you tips I've not covered here. In fact, I'd like to see other tips by others.
Guess where I learned my stuff! The answer is here, and of course Clive's books too. He's a member here, and he sells his books in the Treasure Related Stuff For Sale forum.