I took off four months when my first child was born. It will come back to you fairly quickly...just keep practicing! Also, the textbooks (if available to you) can come in handy to remind you of what you were taught. One thing that helped me was to attend a lower belt class for a few weeks just to work on those areas.
I just got back from my honeymoon, so for about the last 3 or 4 months it's been tough to keep a consistent workout schedule while planning a wedding. As far as techniques and forms, I try to go through them in my head when I'm in the shower or driving to and from work. The part that is getting me is being out of shape. Since I didn't have time to get in enough workout time, my forms and kicking are suffering a bit. My goal before Christmas is at least 4 way forms (maybe 8 way) all the way through Baek Pahl Ki Hyung in good stances and smooth motions.
