Honestly the biggest thing I learned is you gotta check everything twice before hitting confirm. I got burned bad last year when I assumed the system auto-saved my progress but it didn't, so I lost hours of work. Now I make it a habit to screenshot or copy important stuff before committing to anything, just in case. Also testing on a small scale first is a lifesaver, no matter how confident you feel. It's annoying but better than the alternative (trust me, I know). Really saves you from those nasty surprises that sneak up on you.