We did the pre-paid tipping thing on the Valor in early May and that is undoubtedly the best way to go.
Right off the top they add $70.00 for each adult on your sign-and-sail card. After that it's entirely up to you who you tip and how much.
When you order a drink at any one of the bars on board your 15% gratuity is automatically added.
Rosies and similar places are free so tipping someone there is really a matter of choice on your part but isn't typically done; at least I never saw anyone tipping the waitstaff (well, the people that bus your table anyway.)
As soon as we boarded and met our cabin steward I tipped him a $20.00 and I always had ice in my bucket and the cabin was always cleaned and well stocked.
If you play in the casino and you have a cocktail waitress or waitguy that's extremely attentive..go ahead and tip them with a five dollar chip when you leave. They'll be thankful and will remember you if you ever visit the casino again.
One last thing...at the end of the cruise you'll most likely be asked to tip the Maitre 'd. That'll happen at the last dining. I didn't tip him as I didn't see him once during the entire cruise and didn't feel he should be tipped...even holding his hand out collecting the little tip envelope.
Keep in mind that the $10.00 tipping charge CAN be adjusted at the end of the cruise if you feel you've had lousy service overall. How many people actually do that? I dunno. But one thing I do know is if you feel your service is sub-par then by all means say something then and don't wait for it to ruin your cruise for the week.
Whew!! finally..as I said...I didn't tip the Maitre 'd BUT I did tip our head server Julia and her assistant Pande well...they made dining in the Washington dining room at 8 o'clock a magnificant experience.
Hope that helps...