As I reflect on over a decade of experience as a Paralegal, several things jump out at me that seem worth mentioning in passing:
Mistakes are inevitable. Everyone makes them. How we react to mistakes, fix the problem and learn from the experience is what separates good from great.
For as much as we complain about the Attorneys we work for, their existence provides us with jobs. The most basic Paralegal job description is to make our Attorneys' lives a bit easier. That seems like an oversimplification, but it's the core of our profession. We do our jobs to let them focus on theirs.
Everyone needs a coping mechanism to deal with the stress of the job. Just don't let your coping mechanism become another source of stress, like I did. My coping mechanism was alcohol, which led to alcoholism. That won't be the case for everyone, or even most, but it can happen.
Use whatever time off your employer gives. Don't let your employer bully you into not taking your days off. That's happened to me at a prior job, and is happening to a fellow paralegal at my current employer. The firm's time is theirs, but your time is yours. Never let that change.
Never become indispensible. Always make sure there's someone else at your firm who can do all the things you do. This is a two-way street, so learn what other people do also. You can accrue knowledge that comes in handy later, and by helping co-workers, you accumulate favors that can be cashed in later.
Staying out of office politics when possible is a very liberating policy. By not knowing who's trying to do what to who, you don't have to lie if someone confronts you about it. Engaging in office politics is the surest way to make enemies. Staying out of it minimizes the chances of making any.
Feel free to share any short nuggets of wisdom you may have in the comments.