I have probably a half dozen shirts that I've worn repeatedly for 25 years +, easily 100+ washings, and they are still good. Then another set of old favorites that look like they are old, not faded, but seriously cracked. I use a normal wash cycle, cold water only, then 10 minutes in the dryer on low, then onto hangers to finish drying. No shrinkage with that. Of course, it's in my home, not at a laundromat, so it's convenient to do it that way.
Steve