To not do a force start. Not sure if that's a valid move but I'd rather not risk moving anything. If Seikos are anything to go by, I have friends who have those running more than 20 years without a service. Depending on the model, might actually be cheaper to just buy a new Seiko :p
I also think one of the reasons why it's been running ok for so long is that I hardy wear the thing. I used to wear the hell out of it for the first few years then it just started to sit in the box.