I love the simplicity of boutonnières like Fred Astaire's below:
Prince Michael of Kent's lone yellow rose is just perfect:
I think a single blue cornflower would also look lovely on Andy, such a great color for him and it would be stunning pop of color on a simple black Tuxedo he plans on wearing!
These from Artfool are also lovely, great use of berries in the first:
This use of fern in this boutonniere is really striking and unusual, I love it but think it would be better for a pale suit:
LOVE the unopened Jasmine buds in this one also, so gorgeous!
& lastly, I love the Swarovski crystal frog used in this boutonniere! Paired with a single full rose it could stunning... if Andy would agree to it!