I've only started brewing my own
e-liquids, so can't say whether e.g. one of these:
Microbrush® Applicators - Lee Valley Tools
chucked into a variable-speed Dremel is ideal. But it sure seems to work. Small enough to shove down the
throat of a 10ml bottle & beat it to a froth, long enough to reach the bottom of a 60ml bottle & do the same, stiff enough not to flail around like a dying snake.
Just make sure the bottles aren't full to the brim or you'll have
e-liquid everywhere. And shake up the rest as usual.
If you need to REALLY shake up a full bottle, try taping it to the blade of a variable-speed Sawzall, or better yet try a pair of bottles, one on either side of the blade to balance the load. Don't try this with a single-speed saw!
Oh yeah, and make sure the lids are on tight...
Happy mixing!
