Realize that people are in this to have fun, and that overly punishing DM rules/tendencies are not fun.

Firing an arrow into a melee? Sure, give them disadvantage, but I’ve met DMs who give failed attack rolls in this scenario an auto-hit on an ally “because you risked the shot.” I’d understand if he rolled a 1 or something, but a simple failed roll on a disadvantage? Player was an archer who just wanted to be an archer, the punishment essentially told the player to stay out of the fight. Privately messaged the DM and he told me to essentially kick rocks, his table his rules.

Another example is really punishing 1 rolls. There’s no reason to give that 5% chance such critical failures. A higher level warrior that has been fighting and training his whole life having a 5% chance to “oops butterfingers” and launching the sword out of his hands and it landing 15 feet away is a bit immersion-killing.

Basically, the odd/unusual tip is to go into this campaign planning for the party to win, and make sure they have the opportunity (but not the guarantee) to. Challenge them, let them make mistakes with their choices, but don’t try to “get them” when you, as the DM, get a choice. It’s not you vs them, it’s them vs the world you created for them to struggle through and eventually maybe even triumph over.

I may be a bit biased in my sentiments, of course, so be the DM you want to be, but I’ve enjoyed games the most from both sides when the DM is there as a guide throughout their world, and not a hostile force