a bit confused, you don't mention nic or what base or if you got both VG & PG to add to it
you are using concentrates - so you will be adding say 5~7% of each tops, in a small 10ml bottle
(I'd say start by adding say max 4% of each and see how it goes which is more dominant concentrate)
your best bet is have a play around with some figures......
https://www.steam-engine.org/juice.html
add say 10 drops of each maybe to an empty 10ml ??
top up with base halfway - shake like fuck, top up to 10ml and shake like fuck again etc.....
drops are never ultra accurate, syringe scales or fuck it mix massive amounts for accuracy
but you should be able figure some stuff out yourself if you have a play with calculators like steam