Learning from an owner annual

For those that do owner assisted annuals now, how do you compensate the
mechanic for misc things like the use of his tools, use of misc parts
(screws, fluids, etc)? Do you pay a flat shop use fee? Do you just make
sure to put something extra in his hourly fee for the work he did? Its
amazing to me how generous A&Ps are to open their tool box to pilots.
In the automotive maintenance world, if you touch a mechanic's tools
you'll probably get hit upside the head. Loaning out tools is almost
unheard of with cars.

-Robert