Barista
No tip required, though many suggest throwing coins into the tip jar.
Bartender
$1/drink (or 15% of total bill). Pre-tip for better service.
Delivery person (including pizza)
10%, $2 minimum (also, also)
Maitre d’
$5-$25 for special efforts
Takeout
No tip required unless something special is done
Waiter
15% for adequate service, 20% for exceptional service. For poor service, leave 10% or less. It’s okay to leave nothing for exceptionally poor service, but only if you’re sure it’s the waiter’s fault.