Maybe you want something more specific but:
I get an annual physical with my primary. I leave that until the Fall so after summer cycle (typically longer but mild) and I'm cruising for a bit. I do my own bloods in advance post cycle to ensure recovery and that I'm doing okay or on the path. Last summer cycle was mostly test and primo so bloods were fine at end.
I'll do bloods likely another 4 times a year. More if something was really off maybe.
As far as donating, I do it as needed. Less now that my sleep apnea is under control via CPAP. I have always sat at upper human range (say limit is 51,I'm never below 48 and if I'm 51-52 that's okay). You can drain your iron if you overdo it.