1) Set cap types
2) Define target
Define the target impedance you need from DC up to the frequency you specify. This is normally given by the devices driven from this specific supply rail. You may have to guesstimate, if the device manufacturers does not supply good data on the real requirements.
3) Hit Optimize
The optimizer will try to find the minimum number of the specified capacitor types, to fit the impedance curve under your defined target line. The optimizer is randomized, so one run may not yield the same result as the next.
Also notice that only the cap types, where NUM is set to a non-zero value are used.