* Use removable insoles to keep your feet warmer (mostly on land when standing in a cold base), make it easier to get the inside of the boots dry (completely remove the insoles for drying) and cushion your feet (also when walking on land).
* Make a habit from day 1 of waxing the zipper, chalking the seals, etc. exactly as & as often as the manufacturer recommends.
* Help other people understand the cost of the suit and the importance of its proper care (my teenager manhandled my year-old suit and managed to bend & break the zipper). Have also had my suit on a hanger where liveaboard crew caused the neck seal to get exposed to the wear & heat of friction (ouch). Do remember the more flies with honey approach though.
* A tricky leak can sometimes be found by looking with the suit inside out. Wearing white cotton as an undergarmet and making a brief dip can also show where the leak was.
* If a new seal is too tight, at least consider that it might be stretched to fit instead of cutting it. It will stretch in time anyway so I've felt better just advancing the speed of stretching instead of making the seal opening permanently larger.
* You can use bunge loops to secure stuff in your pockets - everything clips onto the bungee.
* Don't ever discuss suit for bouyancy vs. suit not for bouyancy unless you want 50+ people to discuss their somewhat strong opinions ad infinitum.
* Expect to have a slow learning curve with the suit. If it takes a dozen or even 2 dozen dives to never get floaty feet other other pblms. don't let it bother you.
* Learn to make your very own series of checks before standing up or otherwise preparing to enter the water:
1) breathe reg 1 4x while watching air gauge, 2) breathe reg 2 4x while watching air gauge, 3) check that air goes into wing/BCD, 4) check that air comes out of wing/BCD, 5) check that air goes into suit and it distinctly inflates, 6) check that air comes out of suit and squeeze a bit to make it deflate.
Do this and you won't easily enter the water with your drysuit zipper open.
* Amazing much water (2-3L) can enter from the neck if the seal gets a little fold in it, seats itself over some neck hair, etc. The seal can also move into this kind of unfortunate position in the middle of a dive so know that the suit does not necessarily have a leak in it. A no-hole leak can also be a wrist seal seal sitting over the indents on the inside of your wrist or a leak in the air vent vaused by keeping it 100% open (esp on an older suit).
* Don't give into sticker temptation and buy a suit that you know in your heart of hearts is too small, too big or unreliable (i.e. it leaks, or it will soon once again start leaking). The happiness will wear off very soon but the aggravation will last forever.
* Believe what everyone tells you about not wearing cotton or other non-wicking garmets against your skin. I've seen modest types waste so much warmth and happiness on so many dives before finally giving up the cotton t-shirt or cotton briefs (teenagers clinically deaf to advice).
* On 3 completely different occasions (different years) I've had a very tiny little blockage ("blockage" although the problem is that it keeps something from shutting properly) in the inflation nozzle or suit inflator that makes the suit "stealth inflate". The air coming from the nozzle is too slight to hear or feel but it does accumulate. Take note if you notice that you are dumping air now & again but haven't added any air / not nearly that much.