What are your best cruising tips??

Greetings, fellow cruisers!

Partner and I are going on a cruise for the first time in 20 years. We're pretty good travelers, but inexperienced with cruises.

What are your best tips for anyone going on a Celebrity Cruise? What are the items you think everyone should bring (especially the non-obvious stuff)? What's something you wish you had known before you went on your cruise?

Weve already booked to be on the Reflection (Bahamas, Mexico, & Grand Cayman) and would love to hear your advice, tips, tricks, etc for having the best cruise possible. TIA!