They don't have auto-tips but you can have your TA automatically add them on your invoice or you can apply them when you board the ship. If you add them to your cruise prior to sailing you cannot make any adjustments. Also, if you use choice dining your tips must be paid upfront.
Other than that - you can make your own decision.
More than 300 days at sea so far with many more to come. (Actually more - one of these days I'll count them properly.)
Celebrity Solstice - Feb. 21/15 (moved out a year due to illness)
42 cruises - too many to list however cruiselines are in no particular order:
and some unknown tub
Yes, I'm a Royal Chump and proud of it.