Normally I tend to tip about 20%, so for a bill of $49 I would probably pay $60 and for a bill of $79 I would give $100.
Lately I have been wondering how tipping should be handled for larger bills, not in a scenario where there are many people in the group, but rather when the restaurant is expensive. For example I have paid $300 for a dinner for two a couple of days back. I ended up tipping $25. Now in a way giving the waiter $25 feels like quite a lot in absolute terms but percental it wasn't even 10%. Was I actually stingy and should have tipped 15-20% of $300, that is up to $60?