I usually:
1) shoot a roll of B&W (outdated and/or J & C 200) so I can develop it and check for really obvious problems, like film advance failures and badly sticking shutters or apertures; and
2) if the B&W indicates usable results, invest in a roll of E6 transparency film and processing, to check the accuracy of apertures and shutter speeds and, if there is one, the meter.
I always use a hand meter in incident mode, and choose representative subjects.
On at least one of those rolls, using a tape measure and some coloured paper I photograph a fence outside my home that serves as a check on rangefinders or distance settings.
Be sure to take the camera out into the sun and let it be exposed to bright light from a variety of directions - that will help check for light leaks.
Matt