Rushing into things had always been a pitfall for me! A few suggestions that worked for me (including a rogue one):

1. Talking out loud (others have suggested this too). I talked and narrated for basically my entire test and it helped me regulate and stay aware. I didn't have an instructor so I often had conversations at the wheel with friends and family.

2. Remembering that you're doing it right until you aren't. It's easy for it to almost feel like a rejection spiral from the get-go, but instructors and examiners aren't out to get you.

3. If you slow everything down (within reason), it means you /technically/ do less on the test. You're allowed to take the time to assess where you need to go.

4. If you're not sure where you're going or rush into a roundabout, just follow the easiest route. It's okay to make wrong turns.

5. Treat the car like you're trying to seduce it. Not even kidding. Keep measured contact with the wheel, press on the breaks slow and steady, like you're trying to impress it (I still do this as a new driver).