Manually tracking who's due to renew is one of the more thankless jobs in charity admin — it doesn't take long for spreadsheets and memory to drift out of sync with reality. CiviCRM's membership module handles the actual tracking, and its scheduled reminders can handle the nudging too.

Set reminders to go out at sensible intervals before and after the renewal date, and let people renew online themselves rather than needing someone to process it manually. It won't get you a 100% renewal rate on its own, but it does mean the people who intended to renew don't slip through simply because nobody got round to emailing them.

It's a bit of setup once, and then it just runs quietly in the background — which is exactly where you want this kind of admin to live.