A few that come to mind all just random thoughts:
1. Guys, don't forget to pack those black socks/dress shoes for formal night. Saw at least a couple guys on our recent cruise in suits and tennis shoes...Looks ok on David Letterman but...Well, you get the idea lol.
2. Even if you live within close enough flying or distance to the port your leaving from, fly out the day before and spend the night at a hotel near the port if you can possibly get the extra day off and can spare the extra bit of $$$. On our recent cruise we got up at 3:30 am to get to the airport, fly out etc. It went ok, but it would have been so much nicer to have just flown out the day before and relaxed....This is one lesson I learned for next time.
3. I've posted some about this before. Get to know your staff well especially your room steward, waiters etc. They are interesting folks and have interesting stories about their families, home countries etc. Then tip them at least a bit more than expected especially if you had good service from them. As I've said before, we were suprised how many freebie drinks & take home goodies we received without ever asking for it just because we took the time to get to know the staff/crew a bit.
4. Hit the pool on a port of call day and cut the port a bit short if you don't have something major to do while there. You'll probably have the whole thing nearly to yourself.
5. Don't request a table just for 2. You'll miss out on getting to know some nice folks. Even if you are like me and not a real extrovert, it is a neat part of the whole experience. Saw some couples who did the 2 only at a table thing while on our recent cruise and they also tend to be stuck in corners or in the very back of the dining room. They almost stick out in way and looked a bit lonely after a couple days.
6. Go in with a great attitude and roll with the punches even if some things don't go perfectly...Have a sense of humor about things. Pace yourself and just relax.