1) Make sure every practice to address each kid at least once.
This doesn’t have to be even related to the practice, but speak with them and use their name once.
2) Set realistic expectations.
It’s a 12 game season, so let’s divide it into 3 chunks. 
We expect the first chunk that we’ll lose all our games.
The next group, we want to reduce the amount we’re losing by, and maybe even win a game.

The last 4 games, we’d like to win 2/4 games.
That’s our team goal.
3) Playing time
Allocate playing time across all players such that you win enough to keep interest and reward improvement - every player gets better with the goal of each making their high school team