2. don't be independent when writing code: don't go into development mode and start creating a lisp compiler in the project without telling anyone. Check that what you're building is ok with others.
3. copycat the style: you need to adapt to the style of the company you're joining. Whether it's variable naming, or the way they do unit tests, it's great that from your first commit you show that you'll blend in.
4. don't mention the way you used to do things. It's _very_ tempting to complain about things that the new company does less well than the old one. Do not do it, or only when asked.