It's not about cheating or becoming dependent, although those are real concerns. But what drugs do, is to push you past a boundary that you would not otherwise cross yourself. They essentially help you realize and experience what it feels like to be relaxed, confident, mentally turned on, assertive, bubbly, etc. Once you feel it, you start to learn how to get there without the push. Although that does require self-awareness and introspection.
As some have mentioned, the safest and most effective one is alcohol. One or two glasses of white wine should do to start with. I personally find any hard liquor to be terrible in this regard. Personally, alcohol lets me keep a more natural eye contact and mellows my movements and facial expression.
Caffeine helps me think fast and be on, and it lifts my mood up and makes me talkative in social situations (sometimes a little too much). I've picked up techniques that helps me get there without caffeine.
I found phenibut to be an eye-opener when it came to feeling relaxed in muscles. Helped with my posture and breathing. Up to that point, I literally did not know how to loosen my abs and chest muscles to get a nice straight back. It even helped me walk more steady and confident. The confidence that comes from a good posture surprisingly translates into better social interactions! I only took phenibut once a week or so for a few months many years ago and stopped. The learning stays with me to date.
Beta-blockers have helped me stay chill under stress. I'm very prone to stress and panic attacks. This one's a quick fixer - haven't learnt anything from this one.
Magnesium also has a chill effect and it's something you can actually take on regular basis for other benefits.
As always, read about whatever you're about to try, thoroughly and only from scientific sources.