1) Projects always take longer than expected.

There are inevitable delays and bumps in the road. So estimate how long a given project will take, then double or triple it to get the actual time it will take.

2) Always assume an experiment will fail.

Don't be discouraged, and include controls that allow you to troubleshoot the reason(s).

3) Find your niche.

Try different things. You want to find what you enjoy doing that gives you an advantage.

4) Learn how to sell your work.

Sometimes results speak for themselves, but often a strong narrative/story for a paper, talk or job interview is crucial.

5) Most scientists are not out to get you.

Rejection is the norm, don't take it (or negative reviewers) personally. If others don't understand your paper/ideas then it's on you to express them more clearly.

6) Network as much as you can, go to conferences.

You can always use more collaborators, more reviewers who know your work, more letter writers - and who knows where your next job will come from.

7) The line between collaborator and competitor is blurred.

Today's competitors are tomorrow's collaborators, and vice-versa, so don't alienate others unless you have a very strong reason to do so.

8) Look out for yourself and know your limits.

And don't feel bad about taking breaks/holidays.

9) Trust your mentors but be prepared to ignore their advice.

Listen to your mentors, they (normally) want the best for you. But also be prepared to ignore their advice because nobody knows your circumstances as well as you do.

10) Don't compare yourself to others.

There will always be folks with more papers, publishing in higher IF journals. It doesn't matter. Do work that makes you happy.