A method of making a catheter balloon or other expandable tubular medical device or component thereof, in which an assembly of heat shrink material on an outer surface of coaxially disposed first and second tubes is heated to radially shrink the heat shrink material and reduce the outer diameter of the first tube. In a presently preferred embodiment, the heat shrink material extends at least along a central section of the first tube to reduce the outer diameter of the first tube at least along the central section of the first tube. The first and second tubes form the outer and inner layers, respectively, of a multilayered balloon, which has an improved low profile outer diameter.