When I started mixing I did not get much right.
I think I vasted near a bottle of Platinium before it got close to vapeable.
Part of learning I guess
I strongly suggest to not make any bigger batches when 5ml to start with.
And dont get to dissappointed when you fail, because mistakes are the best source there is to learn from.
Start low on the percentage of the flavour, it is much easier to add then decrease flavour.
10% could be just right, if not just try to add 1 or 2 drops more...
Stronger flavours like mint, absinthe and some of the energy drinks are like 7.5% in the premixes.
It is also good to get a atty good for direct dripping to try out your mixes.
I use a C atty. They are not ideal for direct dripping but they are excellent for trying out flavours since
old flavours dont stay long.