Every airline will have its ups and downs. Don't immediately jump ship to somewhere else when your airline hits a roughpatch unless you're the one getting forloughed.

Everyone is expected to know their job and to accomplish it by the FOM and FM. That being said, this profession has two job discriptions.
FOs: Every Captain might do something a little different. Be a chameleon. As long as you think it is safe, legal, and not going to get you in trouble, generally just roll with it. Even if it's not 100% according to the FOM.
CAs: Mentor, encourage, train when needed. Above all, don't be an a$$.

Don't move for a company unless it's to a long standing hub. Every other domicile is just as likely to close as open.

Seniority is everything. Figure out where you want to end up, research what the best way to get there is, and attack it and don't stop until you get there. If your dream airline doesn't call, but someone else does, consider giving it a chance. You may like it and they might still call.

Don't be a slam-clicker. Hang out with your crews. Doesn't have to be every single layover, but it's a great time to ask non-flying questions about bidding, union stuff, ways to work the system, and how not to screw yourself when doing same.