I have 27 juices now and have a hard time remembering what each one tastes like if I haven't vaped them for a while. So what I did was buy a few boxes of 510 XL cartomizers (the long ones) non-punched and put a different juice in each. I can attach the carto, without tank, to my device and put a drip tip on it and give it a vape or 4. I can drip 4 or 5 more drops in the carto if I haven't made up my mind and vape some more. You could vape all night like this if you don't mind dripping some juice every 4 to 6 toots. I get a great vape and good flavor so I know exactly what that flavor is and if I want to fill a tank to vape it for a while. After I'm done with tasting the juice I put the condoms that it came with back on each end so it holds he juice and rubberband it right to the juice bottle so a month later, or whenever, I can taste the juice again if I forgot the flavor. I get these cartos for $8.00 for 5, so it's inexpensive and each carto has only seen 1 juice so there is no flavor mixing issues. I love different flavors all the time and this helps me decide what I want to vape that day.