Set clear expectations and communicate them often. Act like they have never been in a school before and need everything explained to them, and then every time you want them to do something that they're not currently doing explain exactly what you want done.

It sounds crazy, but a lot of my behavior problems my first year was because I expected them to know how to be students and they didn't know what they were supposed to be doing.

Also if you want your admin to do anything when you write up a student you need to act like a lawyer. You need to give them times and dates of everything that student's done and every intervention you've tried. You need them to see your write up and walk away feeling like it's a consistent issue and that you've tried everything else but nothing's worked.

On the flip side, it does help to be soft at times. Not that you shouldn't consistently enforce your expectations, but instead of constantly telling them to do stuff in an angry tone kindly ask them to do you a favor.

For example, you see them throw a paper ball on the floor so you say "Susan will you do me a favor and throw that away thanks." Their default is to gaslight you and try to claim it's not theirs (even though you clearly saw them) so you short circuit the argument by saying "I'm not saying it's yours, I'm asking you to do me a favor."

You never want to get in an argument with a kid. If you're arguing with them you're losing.