I do everything at recommended intervals....

...but then again, my mechanic is a personal friend. He charges me rack rate at my insistence but I know that when he says something is wrong, it really IS wrong, KWIM?

The one thing I do myself is changing the air filter. Anyone who can put gas into a car can change an air filter. Biggest PITA for that one is ordering it from the autopart store and the extra trip to pick it up.