[We are delighted to welcome Lance for a guest post, the advice in which we heartily endorse.]
Here's the best way I know of to expand your repertoire of drink. Sure, there will be some regrets in there, but you'll also end up exploring new vistas and make new friends along the way.
1. Find a 'favorite' bar. This can be one you just wander into, or one attached to a restaurant. What's important is that it's not too busy, but it's not empty, either. You'll know it when you see it. It should have a wide, vast, unruly, impossible collection of liquor easily visible. Hundreds of beers on tap? Only if you want to learn more about beer. Avoid "themes" unless, again, you want to explore that theme (e.g. tequila bars, tiki bars, sake bars and the like).
2. Sit at the bar. At the bar. Not near it. Not standing. Sit on a stool at the bar.
3. When asked "what'll you have?" answer, "I'm in the mood to explore, if that's okay." If the bartender is a good bartender - meaning this is his or her only job and they love it, they should immediately smile. This is an opportunity to show off, or provide something special, or introduce someone else to something they love. If that doesn't happen, and they frown or sigh or look put out, this isn't the bar you're looking for.
4. They should respond with, "What do you like?" What that means is "Based on what liquor?" So you answer "gin" or "vodka" (boooooring) or "whiskey" or "tequila" or whatever. You could also say, "Surprise me," and they should be okay with that. If that doesn't happen, and you end up with a Martini, this isn't the bar you're looking for.
5. At some point, share your name and ask theirs. Who knows, you may become a regular here. Names are nice to know, and also nice to share with visitors, as in "Go to this bar and ask for Janet. She'll do you right."
6. Having settled on a liquor, what else do you like? Sweet? Bitter? Herbal? Fruity? Something like this drink, but nothing like that drink? Are you allergic to anything? Like, what about egg whites? Basil? anything that should be ruled out, rule it out. You're not offending anyone, the bartender wants to make you happy.
7. Then sit back and leave yourself in their hands. Tip well. If you like it, say so. If you don't, say so. Ask to see the bottle(s). Ask for a straight taste. Watch as they make the drink so you can make it yourself if you want to.
This isn't something you're likely to do while awaiting a table or if you're in a hurry. This is a drop-in and hang-out thing. Shoot the shit with the bartender. Introduce your friends. Relax. Sip. Enjoy.