I try to remove mine just as soon as they appear to be in active growth. They seem to root easier then and don't wilt back as bad. You need to slice through just as close to the mother plant as possible so that hopefully, you'll get a few roots on the pup. That may require a larger pot than you planned on using, but the plant will outgrow about anything you can put it in anyway!

I always dust the cut area of both the sucker and mother with Flowers of Sulphur to cut down on rot. Seems to work so far as I've been doing this for about five years and get better than 80% survival rate.

Here is a link that might be useful: {{gwi:1302359}}