Generally mix a BASE with a 2:1 ratio (2 parts VG to 1 part PG)
eg: 500ml VG + 250ml PG = 66.66666/33.333333 ratio BASE juice
a 60/40 to 70/30 base is a rough starting point
if you chuck in lots of flavour & nic generally suspended in PG then maybe 70/30
(as the PG in flav/nic will lower the final ratio more)
if you chuck in more subtle amounts then 60/40
but for ease of maths - nah fuck it 2:1 or 66/33 will do for base ffs
take 10ml, 50ml, 100ml BASE - suggest 10ml for first steps/taster bottles
how much flavour 10~15~20% (wise to start with 10 or 15% max but depends on flavour strengths/concentration)
how much nic 3~6~9~12mg (assuming you have 72 or 7.2% nic)
now really you should use something like steam engine juice calculator to work shit out
but if you have a rough idea of levels & shit you can cut out a fair bit of ratio maths
and run with a general rule of thumb perhaps to simplify it a bit in the mixing stage(s)
really should start with 10ml testers
but for ease of maths I'm going to use a 100ml-ish example
flavour - 10%
take 90ml or 91ml & add 9ml~10ml total flavouring(s)
to make 100ml flavoured base @ 10% flavour aprox
or
take 85ml & add 15ml total flavouring(s)
to make 100ml flavoured base @ 15% flavour aprox
So you got 100ml flavoured base mix or shortfill if you like
based upon using 72mg nic
add 4% or 4ml nic to flav base = 3mg nic
or
add 5% or 5ml nic to flav base = 3.6mg nic
or
add 10% or 10ml nic to flav base = 6.55mg nic
or
add 15% or 15ml nic to flav base = 9.4mg nic
or
add 20% or 20ml nic to flav base = 12mg nic
DISCLAIMER - I'm not suggesting use the above calculator as an initial mixing guide
NOPE
BUT - once you have established a "rough idea" of what you are aiming for
you can simplify stuff very easily
by mixing a base up of 2:1
drawing off say 85~90ml base, add 10~15% flavourings, then say 5~15% nic to suit
You MUST triple check your maths (and mine) using steam engine
but once you have done a few testers you will probably establish a rough recipe/formula for yourself
My post was how to help you simplify it than an actual set in stone rule book
I go with a 2:1 base, take 250ml base add 10% (25ml) flavour
& then just under 10% nic (another 25ml of 72 nic) - this lowers the final ratio(s) slightly
to arrive at a final 59/41 ratio at 6mg nic with an aprox 9% steeped flavour for my ADV
THIS IS NOT SET IN STONE - I use a basic 2-part flavouring
maybe add a tiny tiny shot of something to liven it up now & then but generally rather simple (like me)
the nic level is about right for me, but others will need to adjust to their own level or add more etc....
But again, if you can establish a rough idea of what you want
then you can save a lot of agro or extra hassle by trying to simplify the ratio/mixing as much as possible
this is NOT a guide as such....
mix small testers in 10ml to begin with
use steam engine or other calculators to check you formula/recipes
https://www.steam-engine.org/juice.html#
but once you have gained some experience or wisdom, see if you can simplify it
as it gets a bit mind blowing trying to follow complex ratios/formulas/recipes at times
yes ultimate & final ratios will alter slightly as you adjust the formula a little tweak here n there
but in general, with very minor tweaks the formula ratios shouldn't alter that much
the real issue is trying to formulate a basic flavouring you can enjoy without too much fuss
best of luck