One of my bikes has a little pulley near the bottom bracket. So the cable goes down the seat tube, over the pulley, and back up to the FD. The angles never seemed right, so I also put a twist in the cable to get the pull direction a bit better.

It seems more common for road bikes to be bottom pull, and MTBs to be top pull, perhaps related to the downtube shifters on road bikes from eons past.