At the risk of losing my milk-fed veal reputation, I managed to change my own spark plugs and air filter today.
A couple years ago, I attempted to replace the air filter, and found that I couldn't get the various hoses loose from the bottom of the tank. So I ended up having the shop do it for me a couple times.
This year I figured everything should be looser, so I got my buddy to come by and help hold the tank while I disconnected everything, and with the OEM service manual, replaced the plugs and air filter myself. Now that I've done it, I think it would have been possible to do the plugs without removing the tank, and the air filter by only raising the tank out of the way.
I also finally got the rear suspension adjusted a notch firmer, which we'd never been able to get to budge before.
I really get a sense of accomplishment out of doing these things myself, and appreciate being able to avoid the cost and inconvenience of having the shop do it.
So now I've done my own oil and filter changes, clutch and brake fluid changes, brake pad replacements, and now spark plug and air filter. I'm not too excited about anything that takes more specialized equipment (like mounting my own tires or tackling something like fork oil or carb sync/adust), but doing routine stuff for myself feels great!