I'm not sure how necessary this is, but here's an improved guide for sling bikinis that I didn't lazily throw together in paint in 3 minutes.
https://mega.co.nz/#!TFx2wDzA!Sm_ct<wbr>EGoT0BRRBaC3sKBRiL66Y404BFuZTuhfcXp<wbr>G0QI also discovered that I could do this by locking the color layer. Any Van Halen fans here?