The idea is that you give us a theme. It can be as basic as just a colour, or simply what type of alcohol you favour. Or perhaps something a lot more specific. As an example, my friend did a Macbeth themed one about a month ago. She's very theatrically minded and particularly great of thinking how to present the drinks and dress them up - which is the WOW factor with cocktails really, isn't it? So for example one of the drinks was called a Lady Macbeth and the grenadine was served as blood on the side in a syringe. Another had a rim of syrup as dripping blood.
Then with that theme, she will create a menu of perhaps six cocktails, ideally using overlapping ingredients, so she doesnt need to take a ridiculous amount of bottles around with her. Plus what she's realised is that you can easily use the exact same cocktail for multiple different themes, just by changing the presentation of it. So that rum, vermouth, fassionola and lemon juice cocktail I mentioned above was a 'Queen Of Hearts' when she first did it, with some little rice paper playing cards she got from Etsy or somewhere. Next week she's doing a horse racing themed party for friends, and she's calling it a Red Rum, with cocktail sticks which have horse heads on them. So I think with a repertoire of a couple of dozen different drinks, you can offer a lot of choice.
If people are providing their own alcohol, then I think we'll be up for taking requests, if this takes off. When we first looked into it, I was quite daunted by that - but after spending some time making them, you realise that with a few basic bits of kit, it's not really scary at all. Obviously if you want to get really ambitious with presentation you can, but that's a possibility, if it goes that far.