The same thing I would breed to a plain pastel female, but having the female be super pastel would simply increase the odds of hitting a combo.
If I had the money to have purchased and raised up a female super pastel to be breedable this year, I would likely have the money for at least a male lemon blast or other two-trait combo. As a fairly affordable combo, pairing up a lemon blast with a super pastel gives you decent odds at hitting the super blast.