As they say down under in Oz, G'day Narelle and thanks for asking the Disney Parks Moms Panel such a great question.
Being a Brit I totally understand your tipping concerns; after all no-one wants to make a social faux pas whilst visiting a foreign land!
My rule of thumb for gratuities is simple -
'When in Rome, do as the Romans do' meaning that if it's customary to tip for good service, then I do so without question.
For Bell Services or anyone helping with your suitcases - allow for $1 per bag
Generally speaking on a
daily basis I leave Mousekeeping a couple of US dollars; sometimes I even write a little thank you note placed with the cash near the coffee maker.
At Table Service restaurants - allow 15-20% of the total bill as gratuity for good service and for tables of 6 or more at Walt Disney World Resort an 18% gratuity is automatic.
Bartenders serving drinks can also be tipped around $2 per check.
Valet Parking - allow a couple of US dollars as a tip for your attendant.
Of course it goes without saying that if any service received is unsatisfactory ask to speak directly with a Manager.
On your behalf I found this great
tipping onboard the Disney Cruise Line link which I'm sure you'll find helpful.
Perhaps you could check out the wonderful information provided by the Disney Parks Moms Panel -
Disney Cruise Line Moms; they sure know how to make a cruise truly magical!
If I can sprinkle any extra pixie dust onto your upcoming holiday to Walt Disney World Resort please pop back to ask me another question.
Have a great Disney day.
~ Jane