Congratulations on your impending nuptials!
Gift-giving is fraught with peril. Honestly, I think it's pretty rude to tell people what you want and don't want, and I hate gift registries for precisely this reason. When I am presented with the option of a registry, I don't buy anything from it. (Usually I give handmade needlework pieces that are significant to the couple, or a needlework piece for a new baby that has the kid's name and birthdate on it.)
When my husband and I got married, one of my sisters guilted me into making a tiny registry list on Amazon, but I really wish I hadn't done that. Since we didn't really even have a registry, and we didn't put registry information in our wedding invitations (I hate this), people mostly just gave us cash. Which was lovely.
Some things that we got that weren't cash included a homemade sushi clock, a really nice quilt, two cast iron skillets, and a comfy mattress pad.
About the best thing you can do is to BE GRACIOUS, even if people get you things you don't want. If that is the case, write a nice thank-you note and then figure out a way to get rid of the item.
(Yes, be Mustachian and hope for things you need, but seriously: don't be rude.)