The day lily folds are not completely similar to the traditional lily but at one stage you find a few similarity.The folds start with arbitary folding which is one thing I didnt like cause one maynot be able to decide well. But that is the beauty of art not everything is predefined . you need to experiment to get something new.
You can take both one side or double side colored paper depending on your likings as both will do good.Its an easy and neat model but I would suggest you start with a big paper first time as you may find it bit tough to fold the intricate small folds at one stage.
Origami-Instructions Photo instructions