There is a difference between getting blackout wasted by yourself and mixing a drink or two to sip on. People I've met find it interesting when I bring up that I can make cocktails, most just don't want to spend the effort or time in getting tons of alcohols and gear (despite them being willing to pay $5+ a drink at a bar). But you suddenly become everyone's friend if you start making them drinks.
The egg white thing did gross me out, but for a Bad Touch it had to be done! I think it's supposed to be a texture thing, sort of like shaking pineapple juice, as it becomes a bit bubbley and with a foamy head like beer.
To be honest, I do skimp on stuff like juices and garnishes. Juices I'll just buy bottled, but occasionally I will pay for really good ones. A local grocer sells this bottled key lime juice that's really good and that Costco pineapple juice I mentioned. Garnishes I omit completely and I have yet to buy an ice mold for large "rocks." Glassware wise, places like Goodwill can have some really nice cups! You can also get free shit during the holidays as most alcohol brands start selling gift sets that are at the normal price, but come with some glassware, ice molds, or mixing ingredients. Jagermeister shot glasses are ridiculously nice with their thick, green glass and are marked for a proper shot.
For something in a can or bottle, you could go with a Smirnoff Ice or a canned alcoholic lemonade. Irish creams can be good in smaller quantities. The Costco brand has a chocolate milk/coffee-ish taste to it. Just stay away from premade margarita mix. It's cheap and horrible.