I am thinking a nice picnic basket. Do you think they have one? Maybe a champagne bucket. Any ideas?
I bet they could do with a new set of cutlery. If that’s too expensive, or too old, try this. Either way, it’s better than always eating with your fingers.
Ireland …
I think a gift to a charity they sponsor would be nice. 
sorry to be so boring!
The bodies of their enemies on a barge floating down the Thames?
Presto 03430 Pizzazz Plus Rotating Countertop Pizza Oven
Two of my friends have these and love them. You can bet they won’t get one from any head of state.
A “I Married Into the Royal Family / A Hollywood Actress And All I Got Was This Lousy T-Shirt.” set.
Given their emphasis on conservation as a cause, a nice umbrella stand made out of an elephant foot would remind them of their early courtship in Africa.
Cash is always well received. Maybe the bride could have a safety pin attached to her wedding dress and guests could pin cash(£s)to her chest.
23+Me are promoting their DNA test kits as Valentine’s Day gifts. Could work well here too, celebrating almost complete absence of the inbred royal germline from their future offspring.
Candlesticks always make a nice gift.
Given the long history of the British upper class engaging in bird hunting, I think that a nice Purdey shotgun would be appropriate.
Possibly one similar to this.
… and uh, maybe you could find out where she’s registered and maybe a place-setting or maybe a silverware pattern.
Oh, they’ll probably get some hand-me-down shit from some ancestor or other… you know, the odd monarch, duke, earl, or duke of earl.
I was thinking a break from the paparazzi. I see an opportunity to go in together.
Cash is always appreciated by young couples.
When Charles and Diana were married the official gift from the USA was a large Steuben cut glass punch bowl. I remember this only because of a political cartoon showing Charles falling forward, about to drop the bowl, and Diana saying something about how the President had taxed his subjects for that bowl.
I think I’m gonna send them a nice suit.
I’m just giving them a Walmart gift certificate and letting them pick something out themselves.
I’ve got several sets of steak knives still in the box, from my own wedding. Maybe there is a fondue set in the garage.