The most basic mixed progression is the staggered one.

You start with a limited negative progression line.

Shall you reach this limited negative progression's end, you start another one, with the base unit risen.

Example for even chances:

Stage one: 1, 2, 3.

Stage two: 2, 4, 6

Stage three: 3, 6, 9

Stage four: 4, 8, 12

And so on.

It is usually used with very limited progression lines and some like to throw in a parlay, a la "Risque".