Develop your hand flying skills early and keep then sharp

Learn the manuals at your airline and stay sharp and up to date

Don't waste flights by cruising and being comfortable, keep challenging yourself, keep asking questions of your captains, use every flight to prepare for upgrade

Take CQ events seriously and prepare like its a type ride

Focus on the flight time first- don't get too distracted with extra curriculars early on. Hit the main benchmarks asap (1000 sic - upgrade - 1000 pic)

As much as you can, be nice and respectful to everyone, don't get caught up in gossip & drama, support your coworkers as best you can- when conflict does happen, deal with it in a way you'll be proud to recall in an interview later


*Probably just expanding on a6td's "be a pro" above

I'll add this one thing.. over time you may see people go off to the Majors before you who came after you or maybe people that were a real "joy' to fly with and it irks you to see them move on to your #1 or whatever, but keep a good attitude. Be happy for everyone who moves on whether junior or senior to you. If you let yourself become cynical you will become the person you would have never wanted to fly with and you will take it to your interviews and hold yourself back even more.