I have three 3 year olds - one that easily naps, one that fights it but will fall asleep and one that doesn't nap (which happens to be my own daughter). I have the space to have them in different spots around the house, but they all have their little beds and they all pick out books to take with them to look at while in 'quiet time'. I turn on soft lullaby music and they know they need to stay on their beds until I tell them quiet time is done. If they don't fall asleep they can go watch some cartoons after atleast 20 minutes of book reading (which usually only my daughter does at this point since she is the only one not sleeping). If the others 3 year olds wake up before quiet time is over I let them go watch cartoons too.

Quiet time isn't an option here, everyone needs a rest (including me). The one who fights the nap time has started to come around and she is much more willing to get settled down, it took almost 2 weeks before I think she got that nap time wasn't optional.