One of the most famous independent spas in Seminyak is Bodyworks. The place is located on Jl. Seminyak just up from Jl. Dhyana Pura. If I was into massages I'd be up there all the time. Stopping in today I saw that the place was quiet and the staff had time to talk. All Balinese, they were friendly and laid back and asked if I wanted a massage. I said "Tidak saya glee." (No I'm ticklish). Bodyworks has a reception area at the front and 9 small private rooms located behind. Each room has a bed with bath.
Almost every upmarket hotel in Ubud and Seminyak, not to mention Nusa Dua, now has it own spa. Guests can pamper themselves, relax and rejuvenate. Spas come with herbal baths, whirlpools, traditional massages, mud and seaweed wraps, reflexology and a selection of scrubs. The Balinese are pretty clever when they want to be and can introduce any kind of therapeutic treatment that becomes popular. As well as spas based in big hotels there are a number of walk-in places that are dedicated spas like Body Works in Seminyak (there are actually 2). Most of these spas are open all day until 7pm allowing plenty of time to enjoy the atmosphere and escape into another world.