Shutting down a Cirrus Minor is accomplished in a similar manner to the Gipsy.
1. Shut the fuel tap and run the engine at around 1,000-1,100 rpm to even out the cylinder temperatures.
2. Check the mag switches (two toggle switches) and leave it running until it starts to run unevenly.
3. Once the lumpy running starts the mags are switched off as the throttle is moved smartly to fully open.
4. Close the throttle.
My assumption is that this method allows the cylinders to cool evenly, the mags to be checked and the majority of fuel/fuel vapour to be cleared from the cylinders.