A 'vodka soda water' is usually my choice in a sub-par bar. I specify "soda water" instead of just soda because to some people a "vodka soda" means vodka 7up or whatever garbage they have in the gun. As for vodkas, most are grain based these days (Chopin, Blue Ice and Luksusowa are potato based, in order of preference) though they are distilled so really it shouldn't matter. I do find though, that not all distilled liquor treats me the same way.

martinis are decent but most places don't do them properly and they're a powerful drink, so if you have too many, moderation may go bye bye. Red wine is great if they have anything decent, but I'm a bit of a wine snob and I don't like being sold a fruit juice vanilla candle steeped in wood chips. Life is too short for bad wine and I am opinionated.

Tonic has corn syrup in it, so avoid that. Bourbon is trouble, coincidentally it must be distilled from a majority of corn.

Don't crack under peer pressure to win an account or gain a foot hold in a business meeting. Order what you would normally, and if questioned explain your reasons for not drinking. Nobody likes a "yes man" Values and beliefs are stronger than ever in the business world.

tequila, on the rocks, with lime juice (lots if possible).

I'm with tartare, but my choice in a bar is usually something like "Hi, can I get some seltzer with a twist of lemon and some vodka?" They'll probably still give you club soda, which is carbonated water with sodium (NaCl) or potassium (KCl) chloride in it, and possibly other things. while true seltzer is just carbonated water. That said, it's hard to be picky in that kind of environment, especially when it's usually fast paced enough to get the bartender's attention, and you might be stuck with playing along by seeming congenial when that person you're meeting says "Hey, what do you want?" and you want to keep it simple. Then mayb e just say "Vodka and soda" and scrounge for a lemon from behind the bar. Vodka is generally the most additive-free alcohol, and despite my very serious reactions to wheat due to celiac disease, I have no problems with it at all even when made with wheat (while the littlest bit of anything else has me on the John for a couple days), so that tells me that at least it's transformed enough to no longer really be a grain. Most other spirits are laden with sugar/HFCS/fake sweeteners to make them marketable to the SAD lovers.

I always order patron and club soda with a lime.