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I can't zoom in on the picture for some reason. But I would ice my tiers smooth then chill them a little bit. Then I would pipe those lines on the tiers, put them back in the frig to firm up a bit, pull them out of the frig and flatten out the piping with a piece of parchment or Viva towel. I use all butter buttercream that doesn't crust but you can work with it if it is cold. 

Mid you use crusting buttercream, just wait for the piping to crust and lightly flatten with your hand/fondant smoother and a Viva towel. 

yeah, those are just piped on.

As costumeczar said, just pipe on w/tip 3 making 'wavy' lines around and around each tier.   I wouldn't  chill and/or flatten them out.