Using downsized recipes is pretty standard for me when I'm drinking at home. For a lot of cocktails, half-size or third-size is just fine, especially when you start experimenting with ingredients and ratios. And I have something of an issue with actually committing to a full-size drink (i.e. I often get bored of it halfway through).
However, one of the biggest barriers to entry is the need for smaller glassware, which, while not impossible to source, is limited in its variety. “Where I see a lot of room for improvement is tiny rocks and tiny Highball glasses,” Zielinski says, noting that miniature coupes or diminutive Martini glasses are more readily available.
This is definitely an issue. I've been using stemmed liqueur glasses for small Martini-style cocktails, but even in somewhat smaller rocks glasses a half-sized Old Fashioned-style drink just looks lost.