Originally Posted by gsilliman
If you'd like change in other denominations in order to give a tip in a certain amount, would you ever consider asking?
Most people would indeed ask for change. But I think that the OP's point is a valid one. IMHO , part of professional, gracious service is for the server to go to the trouble of securing proper demoninations.
My very rough guidline for a moderate cost restaurant is to tip 20% of the pre-tax amount for good service, or 25% of the pre-tax for really excellent service. Once I had my proper change in hand, I'd probably reduce the tip, maybe by 5 to 10 percent of what I would have given otherwise.
The handling of payment is the final part of what should be an overall pleasant experience. To have the customer walk away from the restaurant on a negative note is not something I'd want, were I the restaurant owner or manager.