So this is the basic wine cork key chain design.
Just an Eye Screw screwed into one end of the cork.
You don't drill first, you just thread it in as you would a wine bottle opener.
Then attach a key ring to the eye.
to attach another decorative element
this LINK talks about how you can add epoxy
once you've threaded in the eye screw
But this is the addition I like the best,
if you go HERE you'll find a good description of how to do this
this shows how it looks using colored, non-cork corks
it also show how you can add beads/charms at the the end
but i think this starts to make it look a little too "crafty"
although i do kinda like the look of adding a tassel like the corks below
the next few are all from the Etsy shop Uncorked:
i love the way they look but i don't know how she does the printing on them
I like the 2nd cork with the printing
could be an interesting way to add
Eat Drink & Be Married
Here's another way I saw it done so that it is labeled for the wedding
but can be removed later for everyday use:
Lastly, I think you could also make it more professional looking
by adding a slightly better keychain attachment
I put red dots next to the ones i think would work nicely: