We auto-pay the statement balance on the due date.
We have two choices when it comes to paying for stuff
1) the mortgage-linked bank account that operates like a checking account with a large overdraft, calculates the interest owed daily, and has transaction charges
2) the credit card, that has no interest charges if paid off monthly, and no transaction charges.
So we make as many transactions as possibly with the credit card, and just pay the statement account automatically, which minimises both interest paid and transaction fees.
For my expense tracking system, I don't bother to track whether a purchase is made via CC or checking - I just record it having been made on the day, and the monthly pay-off of the CC is irrelevant (and therefore not recorded).