They're not crew, the boat is a team. Treat them as such. When the team feels valued, they are more likely to return.
Keep it fun, too many skippers get so focused on winning the fun disappears.
Set an example, put effort into getting the boat race ready, replace broken, worn, and out dated equipment. Clean the bottom. Clean the boat.
The team is there to have fun, learn to sail better, get out of the house, or spend time on the water. They will not be as invested in winning as you are. Did I mention keep it fun?
Too many skippers treat crew as cheap labor. No body wants to work for free and no-one will have the same level of investment or commitment as you will have.
Winning begets winning which retains crew.
Don't blame the team, accept your role and responsibility for the boat's performance. I crewed on one boat where the skipper was constantly out of phase with the wind shifts, at times it was so bad, I thought we should rename the boat Out Of Phase. He seldom took responsibility for distracted driving or missing shifts, however if the crew took a few seconds too long on a tack, he was all over them.
The best times and memories I have of racing all involve days when the team clicked, tacks were good, problems solved, we worked together as a unit. That didn't always lead to a win, however, on those days we were in the front of the pack.
Recognize that PHRF is a deeply flawed system. It sounds good on paper, however, the basic assumptions are grossly incorrect. The imperfections lead to an arms race among the most competitive sailors, he with the deepest pockets will win more often. Your Hunter 34 won't be as fast as a J 105, however, with a fair handicapping system you should have a shot at podium finish.
If you start hearing jokes about Mr. Christian and Captain Bligh, think about how you are treating your team.
And, finally,


