Short answer–make really really sure you have at least one iron-clad way out at all times. Classic traps–freeze level is below MOCA, no VFR weather below, etc. Also, go read any article about tailplane stalls, just to make sure you’re sufficiently worried.
When I was in training for my 20, the Wings Aloft people told me that they had several icing encounters (being northwesterners, they were pretty blase about it) and they told me that it affected the 20 more than most airplanes, at least in terms of initial airspeed loss, and that it did not seem to shed the ice as quickly as most planes, perhaps due to being clean and white.
But whatever you do, don’t get into it unless you know exactly what your bailout option (or two or three) is going to be at all times. Figure that you will be forced to keep high airspeed and won’t be able to hold altitude, and then work your scenarios.
One mistake that has killed pilots is to try to “pop up” when they started picking up ice; trying to gain altitude quickly resulted in a loss of airspeed, and once you get some ice on the airplane you need to throw the stall charts out the window. If the tailplane stalls on you, you’re pretty hosed (and the recovery is counterintuitive.) I think there’s been an Avweb article about this recently.