Entering split payments (2 different payment methods)

Q: How do I enter a split payment, e.g. paying part with cash and part with credit card?

A: This is easier than you might think.  Just click on Payment to enter the first payment, select the payment method, and before you save it change the "Amount to pay" (or "Amount of check") to the amount being paid with that method.  Save that (you may see a warning about the paid-through date since it's not paid in full, just click No to continue), and then click on Payment again to enter the 2nd payment method.