The To-Do list is important. The Not-To-Do list might be more important.

Frequently, I talk to lawyers doing all the right things. Unfortunately, they’re also doing some of the wrong things and, sadly, doing the wrong things can overwhelm all the good you’re doing.

I’ve learned some of the things on this Not-To-Do list by observing others. I’ve learned more of them the hard way—by doing them myself.

Here’s the list:

1. Stop trashing your clients. Don’t talk about how annoying, crazy, stupid, etc. they seem. Don’t do it with your partners, your fellow associates, or your spouse. Just kill that habit dead. Don’t do it.

2. Don’t tell your clients all the things wrong with opposing counsel. Don’t explain what they screwed up in the last case, how poorly they perform in court, or what personal life disaster they recently experienced. It all gets back to the other lawyers, and it all reflects poorly on you. If you’re going to talk about opposing counsel at all, then build them up. Tell your clients how great opposing counsel are so that when you win, you’re the hero.

3. Don’t ignore any correspondence from your state licensing agency. One would think this goes without saying, but the disciplinary records show otherwise. Deal with it first. Put it on the top of the pile, even if your instinct is to avoid the unpleasantness.

4. Don’t complain about your boss. If you’re lucky enough to have a job, then do your job. If you don’t like the job, then quit. Don’t stick around and complain. The only loser in that scenario is you. I’ve got one colleague who complains about her job constantly, and she does it on Facebook. How stupid can you be?

5. Don’t defend yourself. When you’re accused of anything (a disciplinary matter, malpractice, wrongful termination of an employee, or a traffic offense), hire a lawyer. Don’t do it on your own. Get help. You, better than anyone, know the value of having someone competent help you with the problem.

6. Don’t assume you know more and can do better than everyone else (the marketing guy, the IT guy, the financial advisor, the office decorator). You’re an expert in your field, and they know their business as well. Let them help you. Don’t do it yourself: it’s a waste of your time, and you won’t do it nearly as well as they would have done it for you.

7. Don’t slip to the lowest common denominator level of practice. They don’t prepare, so you stop preparing. They aren’t ready, so you aren’t ready. They show up at the mediation without spreadsheets and documents, so you do the same. It’s easy to adopt the prevailing standard of practice. Don’t do it. Keep being excellent no matter how bad your opponent is. Excellence is always better. It’s easy to underestimate your opposition. Yes, they’re usually ill prepared. This time they aren’t. They’re ready, and you’re not. Your client’s going to figure it out. It’s going to be pretty obvious. You need clients out in the world raving about your work, not trashing your reputation. Don’t count on opposing counsel making you look good. You’ve got to take responsibility for making yourself look good.

8. Don’t make derogatory comments about the judges. These are some of the thinnest-skinned people on the planet (there I go again). They find out what you said, they remember it, and they hold grudges. Keep it to yourself no matter how upset you are with the ruling they just made in your case.

9. Finally, don’t skip the celebration. You’ve won a case, you’ve made a client happy, or you’ve settled a matter you thought would never settle—enjoy it. Happy moments are few and far between. Gather your team and go out for a meal, spend some time together, and relive the glorious moments. Celebrate every victory.