You definitely should NOT review your notes immediately before doing reviews. Doing it in between is probably fine in most cases.
And don’t worry about new items ending up in the critical list. That happens pretty often to me and probably many other people.
The best thing to do is probably to review items you just got wrong after doing your reviews, to help solidify them for next time. If you’re comfortable with adding user scripts, you can use these three to allow you to review recently wrong reviews and leeches (items that you get wrong over and over) as often as you want.