About ten years ago, I published a minimal citation style with some additional ideas to further compress the bibliography at the end of a research proposal (see this ancient blog post). Here I add a second citation style, one that I recently used for a proposal to collaborate with Olivier Raineteau and others. The proposal was written for the French research agency ANR, which mandates that the bibliography of references counts towards the page limit (so we want to minimize them, even if we have 20 pages) and that each bibliography item is easy to read and understand.
Taking these guidelines into account, we came up with a minimal style that is a bit less minimal than my old, original one. All in all, there are two differences between them worth mentioning. First of all, the biggest change is that we add DOIs (Digital Object Identifiers). They were less important a decade ago, but over the years have become a fast way to access any publication. No one wants to spend time typing or copying authors, years, and titles into search bars. Second, besides mentioning the first author, we also put the last author. In this manner we recognize the work done by the first author and we acknowledge the context of the work (and the continuity of a certain research line, and reputation if you will) through the last author. I am aware that we ignore co-first and co-senior authors, but if the goal is to be somewhat minimal, this is unavoidable. Luckily, with a DOI one is only a click away from the full author list.
The result is: 
I’ve added the style as a gist to github for ease of use and I hope to save others spending 20 minutes on making a citation style themselves: find it here!
PS: Making your own style is not difficult these days, see Zotero’s documentation.