I try to be very visible to motor vehicle drivers when I ride my bicycle at night.
I attached high-reflectivity vinyl strips
to a pair of work gloves.
The reflector strips extend all the way around the cuffs, so it's visible front & back
when I hold up my arm as a turn signal.
And the vinyl reflective material stays very visible in the rain
Commercial alternatives: I didn't find any I liked which were reasonably priced. Reflective piping is not sufficient; you can't see it very far. Cloth reflective materials lose reflectivity when wet; they are less visible in the rain when you need them the most. These gloves are close: They have good vinyl reflectors on the backs, but not the front, and are pricey: http://goo.gl/eKCJBL
So I made my own...