I have two spreadsheets. One is for keeping track of both past and current credit cards with the following columns: Brand, Cost, Opened, Bonus points, Spend, Spent, Benefits and notes, Annual fee warning, Approx statement date and Closed. I use this to keep track of the important stuff and I use Google calendar on my laptop to set warnings and reminders. I have those synced to my phone. The Benefits and notes section is where I list things like monthly points cap, insurances, earn rates etc. A very handy and easy to update file.
The second one is for keeping track of the different points we currently have accumulated and it’s complete with graphs. I love watching those spikes when you get bonus points! I update it often and I find it an incentive to chase more points. This is a bit time consuming but hey, I’ve got the time