You should have a wind down routine for both. As day sleep and night sleep are organized differently in the brain, you can have slightly different routines for both, as long as they are consistent. i.e. nap wind down the same, bed wind down the same. I found it easiest though to have a curtailed version of the evening routine for the nap. So for naps, you would leave out the bath, but perhaps a story and a lullyby.
HTH