I seldem leave the tip on the card.
I always leave cash for a tip, so the actual server can do with it as they please.
And I always, always tip.
I even tip $1 for every $2.50 beer I drink at the local watering hole.
Yeah, me too. 1) I don't trust the management to give it to her and 2) I don't want to leave a trail for the IRS. Oh, I usually start at 20% for my base tip. I've given 30% tips or more for really good service. I frequent the same places often, and they know me. We're good friends.