Other than the simulating the tone, you can:
For series operation:
1) Wire a resistor between the outer legs of the volume pot, or if for only one pickup or one pickup position, the hot tab on the switch for that pickup /position and ground. This drops the effective value of the volume pot. You can go anywhere from 10M, 5M, 3M, 2M, 1M, 820k, 680k, or 470k depending on how far you need to go. Experiment and see what gets you there.
2) Wire a very small cap on the tone control and roll it down for that pickup. Helps to have a dedicated tone control for that pickup. If your guitar is a 1 tone guitar, you can get concentric tone pots to split things up. For bridge PAFs (7.5k-8.5k range 42ga wire) I find .001uf works great. For anything hotter, 750pf works great. Removes the obnoxious frequencies but leaves the cut and articulation.
For parallel:
If you want your bridge humbucker to sound like a lighter version of itself instead of two bright singles in parallel, when you wire your push/pull or however you put it into parallel, run a .0022uf cap in parallel with a 470k resistor between the 2nd coil's hot and the first coil's ground. This is shorted when the pickup is in series as these wires are shorted to create series operation; in parallel mode it rolls off highs and lets those two coils see ~230k to ground, which is more what a single coil wants to see.
So for standard Dimarzio wiring R+ B -, W+ G-, run the cap/resistor between the tabs where the black and white wires are soldered.
This trick works great for getting a 'vintage' sounding humbucker sound in parallel with pickup that is a hot humbucker in series.