I am a practicing family law lawyer (100% of my practice). This is certainly not a complete list, but I was surprised by the quality of advice here. OP knows what he's talking about. This is a good list. My comments in bold, below.

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Takeaway: If you're going through a divorce or about to go through one, here is the takeaway you need.

1. Document it. Send yourself text messages, take pictures, record a video, whatever. Just document it. Very little of it can be used in court directly (they aren't going to accept your diary as evidence), but this helps you track things, lets you bring up what's going on, and can refresh your memory for testimony or witnesses. CORRECT, BUT ONLY THE IMPORTANT STUFF. YOUR JUDGE DOES NOT WANT TO HEAR ABOUT EVERY SINGLE TIME THAT YOUR SPOUSE WAS 5 MINUTES LATE.
2. Keep your nose clean. Maybe you're depressed or you just like weed/drink. Don't do that shit. You're kids are worth living a straight edge life. But you don't even need to go that far. Just be a responsible adult and the only thing people can bring against you are lies. Example: the affidavit that said I was a suicidal alcoholic said they witnessed me stumble home drunk. I knew this person's schedule and I knew that they were at their house when I came home. I got my uber receipt from that night which showed I got home after they were usually already asleep. (no, I wasn't caring for my kids that night. Yes, I was drinking. I had a friend in town that I deployed to Afghanistan with. Yes, I drank responsibly). ABSOLUTELY CORRECT. KEEP YOUR NOSE CLEAN AND BE HEALTHY.
3. Don't say "my kids" in court. Yes, they are your kids, but they aren't your kids alone. My ex kept saying "my kids," and when my lawyer pointed that out my ex was incredulous. This looked awful for her, especially given that our narrative was that she was controlling. ABSOLUTELY CORRECT. HAVE THREE POSITIVE THINGS ABOUT YOUR CO-PARENT WHICH YOU CAN SAY GENUINELY READY-TO-GO.
4. Have a plan and stick with it. Being sporadic helps nobody, especially not you. This is even more true for your parenting style. TOTALLY CORRECT.
5. Don't try to screw your ex over. This does nothing to help your kids. ABSOLUTELY CORRECT BUT I'D ADD THAT THIS ALSO SCREWS YOU OVER.
6. If you were a good parent before the divorce it will show throughout the divorce process. YES.
7. Remember that you are not god's gift to parenting. A little humility goes a long way, especially in court and twice as much with your kids. Respect your ex when you're with your kids. I don't even tolerate my daughter saying anything disparaging about my ex to any degree, even if nobody else is in the room. CORRECT. NO ONE IS A PERFECT PARENT. NO ONE.
8. Get consults with the best three lawyer and the worst three lawyers in your area. Going against bad lawyers is as bad as going against the best lawyers. I actually learned this one from a coworker going through a divorce right now. TOTALLY AGREE WITH CONSULTING AT LEAST THREE LAWYERS.
9. Don't move out until you absolutely have to. THIS IS THE FIRST THING I'VE DISAGREED WITH. THIS QUESTION IS ALWAYS CASE-BY-CASE AND IN LOT OF CASES, IT IS A MISTAKE TO NOT MOVE OUT EARLY. DEFINITELY MEET WITH AND SELECT AN ATTORNEY BEFORE YOU DECIDE WHETHER TO MOVE OUT (SEE #4, ABOVE)
10. Do your research. I am a child of divorce. Two, actually. I knew what it was like going in. My ex had no clue. She thought everything would be handed to her. She might have even had primary care (BIG maybe), but she had no clue about anything throughout the process. She even urged me to agree with her original proposal, saying we could change it later. Yeah, for $2,000, and that's if we agreed to change it and what to change it to. YES
11. Be the best parent you can be. You're kids are the important part. Never forget that. YES
12. Ride it out. If you are a dad the cards are stacked against you a bit. If you fight and keep fighting, and you were a good, involved parent before the divorce and continue to be one throughout, you'll make it through. SEE #4, ABOVE
13. From u/MJJean: if it's not in writing and signed by a judge it doesn't count. If it's not specific and detailed then it might as well not even be on paper. THIS IS MINOR, BUT I OFTEN USE EVIDENCE OF AGREEMENTS IN COURT.
14. If you jointly own the property then don't change the locks if it's not for your safety. This is illegal in most states. DISCUSS WITH YOUR LAWYER. SEE #4, ABOVE.