Too Long; Didn't Read
Unit Testing and Code Review are the best ways to keep your code stable. Pair programming is an ideal tool to share knowledge in a team. Git and Git version control is often underestimated: being proficient with Git makes you more proficient with the power to make you proficient. Keep it simple: Planning for the unlikely makes code unnecessarily complex. Don't try to foresee your project's requirements two years from now - too many things can (and will) change! You would waste time on an overly complex solution that proves to be different than you thought.