If you want a 'one-stop shop' for your staff, you should consider having a Handbook. This template contains policies on absence, discipline, grievance as well as family friendly policies such as maternity, paternity, shared parental leave and flexible working.
Employers may need to invest in their staff development to ensure they have the right skills for the job – if an employee leaves, you may reserve the right to reclaim some or all of the costs of the training if mutually agreed in advance – this agreement sets out those arrangements.
When employees leave, it is useful to understand their reasons and also their views on your Company. This questionnaire provides a useful set of questions about the individual's role, working conditions, relationships, and reasons for leaving.