Target the people who are most ready to take the next step. These are people who are already significantly involved -- they volunteer often, attend meetings, and/or chair a committee.
Show them you have the resources to help them do the job. A written job description and a binder with key information are a good start.
Let them know they're not alone. Encourage potential new officers to job-shadow current officers. Formalize a procedure in which incoming officers meet with retiring officers to discuss the specifics of the job. Your goal is to open lines of communication so new officers don't have to reinvent the wheel each year.
Here are some more resources that will help you smooth the transition process:
- Officer transition: planning ahead
- How to create a PTO procedures book
- Basic officer job descriptions and characteristics