The 100DT or '100 drop test' is simply where you make your recipe in a batch size of 100 drops.
So, if you use 1% peppermint, 1% chocolate, 1% creme, 2% NIC, 48% PG and 47% VG in the recipe...
You would get a small container that can hold more than 100 drops of liquid and substitute the % for drops, e.g.,
1 drop of peppermint flavor
1 drop of chocolate flavor
1 drop of creme flavor
2 drops of NIC (well mixed in advance)
48 drops of PG
47 drops of VG
Then you need to close the container and shake/mix this up very very well. Since the amount of NIC
juice being added is so small, it may be best to leave the NIC out completely and add more drops of PG or VG as a substitute.
BTW: 1mL of liquid is said to equate to something between 20-24 drops. 100/20=5mL, but this depends on your dropper etc. You just need to make sure the bottle you are going to put these 100 drops is big enough.