Freehand, using a very opaque off-white and dark red. Thinned paint so it flows easily off the brush, but not too thin so it doesn't flood the miniature. A size 1 brush with a good tip that holds the shape well. After painting the initial stripe, come back with lighter colors for the highlights. Clean up with blue.
If freehanding the stripes proves to be too fiddly or too much of a chore, I'd try masking tape.