I cheat and by wood binding with the purfling line already glued on the short side and bend them when I bend the sides. If I want purfling on the top or back of the guitar I sandwich the lines in the channel and wick thin CA into the interface. This sort of shows it - the rose wood binding has a maple line on the bottom, I'm adding another between the binding and the body.
I bought one of those binding laminator thingies from StewMac that uses acetone to laminate plastic binding - using it was kind of a cluster so now I just stack the strips in the channel. Acetone only works on plastic binding, since I use wood, plastic, fiber and the little teflon to hold a gap for pearl my glue of choice is water thin CA. Others don't like it, I've had great results with it.