How do you BYOB with cocktails?

If I were bringing my own cocktails, I would think about bringing something that did not require shaking because shaking is essential to the outcome of hte cocktail, and I'm guessing it would be a little distracting (and messy and inconvenient) to try shaking your own cocktails at the table, even if the alcohol is already portioned out. Great non-shaken cocktails that can be mixed ahead of time and then poured over ice: Martinis (or Gibsons), Negronis, Manhattans. But I wouldn't recommend serving the Martinis or Manhattans up because they won't stay cold enough.

I REALIZE NOW MY QUESTION WAS VAGUE, I APOLOGIZE!

I didn't know BYOB RESTAURANTS were more common in Philadelphia than other parts of the U.S. (if interested see this link: http://voices.yahoo.com/byob-dining-philadelphia-pennsylvania-frequently-6375186.html?cat=16 )

Lolita in Philadelphia is "BYOT" - bring your own tequila ( see http://www.lolitabyob.com/lolita/)

This chowhound thread is what piqued my interest in the first place: http://chowhound.chow.com/topics/830265

Thank you to everyone who responded and sorry for the confusion!

You could announce it as a BYOB specific cocktail party. Decide that three different cocktails will be offered, then assign what bring equally. With a bloody mary someone brings a half size bottle (cost) of vodka, someone brings tomato juice and celery, etc. The problem is cost. And not fair you get the leftovers.
Maybe you supply the cocktail and have guests bring specific appetizers to pair.

I would just take it in a thermos or other container, ask for glasses, and tip.

Yes, there are lots of BYOBs in Philadelphia because obtaining a liquor license is difficult in PA. (I am in the 'burbs). We usually bring wine (sometimes beer for Indian) which is fun to plan and saves money. When I came across a thread about bringing byob cocktails I was intrigued... bringing a drink while ordering and waiting to be served seemed like even more fun but I had never heard of doing so. I appreciate everyones advice about calling ahead to check and tipping well for the service.

We love the BYOBs in Philadelphia, and usually bring a bottle of wine. Last time, though, the table next to us brought what looked like a makeup case filled with several thermoses of margaritas. Seemed perfectly acceptable to the server, who brought glasses and ice to the table. (Always a good idea to tip generously, too, in places that accommodate BYOBs.) If in doubt about what you can bring (wine, beer, or cocktails), just call first and ask.

The only time we've BYOB was when my partner's mother brought a really good bottle of wine. We called ahead and there was a 10 dollar corkage fee. The server waved the free..after we gave him a glass of the wine because he was curious about it---it was something she'd brought back from Italy.

Bringing wine is pretty common but there's a corkage fee. Bringing your own cocktails, well I really don't know--but I think most of those places don't have a license and charge a fee for mixers, ice and glasses.
A friend from Utah called those places "bottle clubs".

Never heard of this. Now I am curious, where can you do this?

I don't know. The only BYOB places I've been where wine only. I have heard about places that let you bring a bottle of booze. But they mix it for you for a fee like a corkage free when you bring in wine.