In my experience, beginners find it difficult to keep track of their construction crew strength.

So I place these little tableau above the tableau that came with the game and give each player four additional token in their color to keep track of each crew separately.

The Crew token is placed in the circle above each track and turned over when a crew has been used during one's turn - as described in the rulebook.

This makes it easier for novice players to understand that each of the four tokens represents a group of workers and that the number of workers may increase in each crew during the game, etc.