Graduated mixing/drip-tip bottle:
This is a 30 mL bottle from Tasty Vapor, with a strip of label-maker tape attached to it. I got this one wrong, but you get the idea.
It doesn't seem like much, but with the tick-marks spaced properly you can quickly mix a bottle of juice, have zero clean-up, and be vaping in just a couple of minutes. Just remove the cap and drip tip, and pour ingredients directly into the bottle up to the pre-marked lines. Replace the cap and tip, shake a few time, and you're done. Replace the caps on your ingredients, and put them away. The only clean-up is the funnel, if you need to use one (I don't).
This was done with a DYMO label-maker from Walmart. Just type a bunch of lower-case "L's" and print them out. It may take a tweak or two to get it right (number of characters, size/style, etc.). I'm thinking if you have a good vector graphics program, you could just use scotch tape to mount a dozen or so strips of the label-making tape to a piece of paper and get the dimensions correct for just about any sized bottle. This stuff sticks to bottles and atomizers very well. It might be worth it to cover the tape with a piece of scotch-tape (that's cello-tape for you Brits) to protect the ink, but I don't know it that's even necessary. They also make "plasticized" tape for the label-maker(but I don't know how the plastic tape sticks). I think they might also have "metallic" tape, whatever that means.

This is a 30 mL bottle from Tasty Vapor, with a strip of label-maker tape attached to it. I got this one wrong, but you get the idea.
It doesn't seem like much, but with the tick-marks spaced properly you can quickly mix a bottle of juice, have zero clean-up, and be vaping in just a couple of minutes. Just remove the cap and drip tip, and pour ingredients directly into the bottle up to the pre-marked lines. Replace the cap and tip, shake a few time, and you're done. Replace the caps on your ingredients, and put them away. The only clean-up is the funnel, if you need to use one (I don't).
This was done with a DYMO label-maker from Walmart. Just type a bunch of lower-case "L's" and print them out. It may take a tweak or two to get it right (number of characters, size/style, etc.). I'm thinking if you have a good vector graphics program, you could just use scotch tape to mount a dozen or so strips of the label-making tape to a piece of paper and get the dimensions correct for just about any sized bottle. This stuff sticks to bottles and atomizers very well. It might be worth it to cover the tape with a piece of scotch-tape (that's cello-tape for you Brits) to protect the ink, but I don't know it that's even necessary. They also make "plasticized" tape for the label-maker(but I don't know how the plastic tape sticks). I think they might also have "metallic" tape, whatever that means.