Something to muddle cocktails with. IDK what that is, but I know it's "in", LOL

http://www.williams-sonoma.com/shop/tabletop-glassware-bar/tabletop-bar-tool/

This is a must. A set, one large and one rail heavy duty service mat. Once someone has had way too many pops this will help contain the flying pour.

A good quality knife for cutting citrus and a small/med size cutting board. You don't want one without the drain well around the edges like the one pictured.

When I first read it, I thought what a great idea for a shower! But the more I thought about it, the more I was concerned there would be a lot of duplicates. For that reason, I LOVE the service mat Justterrilyn shared.

I also like the muddler.. a must have for modern (and not so modern) cocktails!

I love party buckets and trays-- and such a wide array to choose from. rustic to elegant. I have been using a vintage enamel tub that belonged to my grandmother. She could have used it to soak her feet for all I know!!.. now I use it to keep bottles on ice on the porch.

Here's a few I grabbed photos of.. but there are so many styles.

Also, in NYC you can get a great bunch of small batch whiskeys, gins, etc. I'd read reviews and choose a couple of highly rated options with interesting bottles and labels.

Are you supposed to bring accessories or liquor?

I fell in love with this ice bucket from nambe but I haven't seen it IRL.

The top part is an ice scoop.

What kind of bar tenders are this couple likely to be? Gin & tonic, scotch and soda or purchased mixers? Or artisinal cocktail type? I guess I picture a couple that would have a stock the bar shower as more of the later. My first thought was a bottle of liquor or some glasses, but those are more difficult for you to travel with. Or you could pick up a bottle or two when you arrive. Something they probably don't have - Cedilla, an Acai liquer and fashionably purple for fall. It tastes great too, but it's not easy to find. There is a blood orange that would be another seasonally appropriate one. Cachaca is also popular (a Brazillian cousin to tequilla). A bottle of champagne is always appropriate for a wedding. Bitters and shrubs are popular and you could pick something unusual. Carry a gift bag and card in your suitcase so you don't have to worry in the liquor store doesn't have the gift bags. Or they might package it all up for you if you and have it waiting if you call ahead.

Personally, I would shy away from tools, but that is because I have been through buying some with my bartender son. It they are really into mixology, they probably know what they like. If you don't mix cocktails, you won't know what to look for.

There are some great cocktail books that go beyond the standard cocktails -- Death & Co., Liqiuid Intellingence, The Dead Rabbit Drinks Manual, The Drunken Botanist and a dozen more. Look up one on Amazon and you will probably see the others listed too.

Cocktail napkiins -- Rough Linen sells fringed edge ones by the dozen -- they are nice and lightweight -- classy buy casual. I saw some hemmed cotton ones on sale at Sur la Table. Probably nice for more formal occassions. And some fun paper napkins for laughs.

Bar nuts or mixes -- sweet, savory, spicy. A nice dish to put them in.

There are a lot of ice trays and ice molds out there -- large cubes and spheres -- they may have those and get more.

A Vacuvin wine pump and some extra "corks" -- available on Amazon. A wine aerator.

See anything you like? Should I ask my son for more suggestions?

ETA: My son has one of those bar mats -- he would agree that too.

Six Tiffany & Co. Mint Julep Mojito Straws/Swizzle Sticks in Sterling Silver from Ebay:

I want these!!!

From Etsy

https://www.etsy.com/listing/65691679/sterling-silver-cocktail-picks-1-set-of:

sports themed (not my fave, but from Tiffany if they are into sports)

http://www.tiffany.com/gifts/gifts-for-the-home/sports-cocktail-picks-27070132

Copper barware is very popular right now. All the weddings I've been to this year have included some in their gift registries.

Thank you so much for the various ideas! I really appreciate it! I think I have enough to go on. I'm really not sure what types of liquor they drink or tools they use/need. The shower is for my daughter, a partner at a NYC law firm. They like the finer things in life, but have worked hard to reach this point.

Monogrammed cocktail napkins. Fancy coasters (animal print; silver/Crystal).

just gave a very modern NYC bride a set of 8 Kate Spade champagne flutes with polka dots on them.

Kate Spade has matching small bites plates, too.

You may also give Whiskey Glass and Chilling Stone sets. The "cubes" are made of stone or stainless steel and are used in place of ice cubes to chill high end Whiskey - with no dilution!

And I love Oly's Sterling picks! I love all Sterling though.

Copper mugs for Moscow Mules or ice ball forms that make large balls of ice to minimize dilution. The stone sets loonlakelaborcamp mentions are less effective at chilling the drink IMHO. YYMV.

My son and his finance had a similar shower - I forget what they called it but on the invitation they merely asked the invitees to bring along a favorite bottle of wine. They only received a few serving pieces or utensils, most people brought wine.

I gave them a monogrammed sterling silver wine bottle stopper from Tiffany and a Roger Estate wine opener that also re-corks. This isn't the one but it looks similar.

http://www.frontgate.com/granite-base-wine-opener/386346