Set your color model to HSL

Pick a color, any color

Make variations of the L value
Create a set of L values with differences of 10. Ranging from 0 to 100.

Create 10 copies of your original color

Replace the L values

Find your partner in crime
To create your secondary color, add 30, 120, 150, 180, 210, 240, or 300 to the H value of your primary color. For this example, I added 30.
Repeat steps 4 and 5 for your secondary color scheme.

Select a primary and secondary variant

Choose your side kicks