Duct-Style Tapes (really cloth-backed water resistant high-adhesion high tack tape):
Hands down, Gorrilla brand for the heavy duty stuff.
As an alternative, thinner product, 3M makes - in general - the best flexible adhesive products around.

Electrical: Scotch 33, 35 and/or 66. But Scotch for sure, high flex, high strength, good low tem performance.