First, you need to dilute concentrate flavors with PG/Vg.
The Mix ratio of concentrate flavors
the fruit flavor Mixing ratio is 10%-15%;
Mint flavors Mixing ratio:4-8%
T-B flavors Mixing ratio:8-12%
For Russia, the ratio may need more than 4%-15%.
Next, Steeping
After the liquid is ready don't v it immediately, it tastes much better if you keep stocking it for around 2 weeks.
Choose more VG or more PG for making liquid juice.
it is according to your customer's taste, or the people in your area.
VG is thick, sweet, smooth, and foggier;
PG acts as a dilution and enhances the strike-throat feelings