I have made a coffee vodka. Saved the grounds up for days, only to realise you don’t need much to make it! Left it for much longer than the recipe said, but that was because I wanted a stronger coffee taste.

Not sure if you get it in the US the same as in the UK, but I find that even just squash is good with carbonated water, e.g. orange squash. Cheaper than syrups and it tastes good with still water too!