I noticed that as I've been working with MD clothing, I am repeatedly having to strip off attachments, run the simulation, then put those attachments back on. Since wearable items like rigged boots and long hair don't move with MD clothing, wearing them in contact with simulated cloth often causes weird results.
If I strip down, simulate cloth, stop, then wear the attachments, everything looks great. It's just not very convenient to have to do this every time.
(The cool outfit I'm wearing was made by NorthernKiara btw!)