'Guilloche' is a lovely word, and guilloche is a lovely ornamentation, one of my favourites. It's part of a family of decoration that includes Celtic knotwork and Tudor strapwork.
Guilloche is an interlacing pattern of bands or ribbons that weave around a centre 'boss' or button, so it can be considered a moulding - done on a flat rather than profiled surface. The boss might in turn be a floret; the deltas between the looping bands might be leaves; the bands or ribbons themselves might be multiplied - so the guilloche can anything from basic to very complicated.
I've carved a simple guilloche pattern here, more of a modern taste if you will. I've used it on a mirror frame but you apply the ornamentation to other furniture, for example the apron beneath a table top.
Guilloche is a great beginners' exercise! There are so many fundamental carving skills evident here. Why not carve just a short length of it for fun?
The Book that I show in the video: 'Handbook of Ornament' by Franz Sales Meyer (Dover Publications NY)