I use a Badger Air-Brush paint mixer ($12 on Amazon) and a 10-minute hot water bath to cut down on steeping time. All mixes will darken in color to varying degrees and become more complex as they steep depending on the amount of nic and the flavor type. Steep as desired. Fruit mixes typically require less steeping.
I add one drop MTS Vape Wizard per 10 ml to smooth out complex mixes with multiple ingredients.
**As always, adapt nicotine level, flavor percentages, and VG/PG ratios to suit your liking** I mix at 18 mg/ml for pod refills.