No way to order robes pre cruise for us in UK..at least I have never managed to find a box to tick!
On meeting the steward, we give him/her a list of things we would appreciate..ice, wine glasses, robes, bar soap, paper Patters, no ‘Junk mail Effy/ Art Auction’ etc. All requests swiftly sorted.
Robes on our last two cruises seem to be made of a different fabric..more like old fashioned crimplene, so don’t shrink.
We tip cash when steward has gone over and above..which has been always on our 25+ cruises.