i have found regular masking tape to work great. i usually cut squares for for the buckles and let the paint do the work. this works for 1/72,1/48. if the project is larger i'll still use tape but i'll make the buckles from wire and thin styrene. i have tried alum. foil, paper, electrical tape, and a host of other mediums. plain old masking tape wins my vote, even far above photo etch.
i recomend fashioning then and painting then before installing them. tiny dabs of super glue here and there. you can drape them and shape them very easeally. good luck