Beautiful job, Julie!  Like you said, horizontal stripes are not easy.  I saw a tip for applying them once.  The decorator cut pieces of flexible cardboard, plastic - not sure what - to the height of the bottom of the stripe, wrapped it around the cake and used it as a guide to apply the fondant stripe.  She made a guide for each stripe.  Hope that makes sense.

Thank you so much Sandra. It absolutely make sense, I saw a video like that too but I did not have any material on hand to do them this way.