Regardless, it's hard to tell what someone will like. You can read the journals and see what the editor's tend to favor, but even that's not always guarantee that what you're sending will pique an interest (or gain a consensus when it comes to multiple editors.) thank god I run my own operation since sometimes I see something and love it and would have a hard time explaining to another editor why. I just do--for whatever mercurial chemistry of voice, tone, and subject matter that knocks me for a loop. And of course, it sounds like mallarky, to say "I don't know, but I know it when I see it..." and it is much the same with the visual art that I find appealing, but again, might not be able to tell you why. Admittedly, I do take it as a badge of honor when an author admits they've been sending something around and I'm the first yes after a long time of no.
I've always experienced the role as a editor as more of a curator than any sort of gatekeeper. Or hell ,a bit divergent perhaps even from the traditional role of editors in the historic sense. I very rarely dig my hands into the manuscripts in much beyond a copy-editing. I might make some suggestions, but usually these are based on formatting and layout concerns. And I tend to say no to things that might need a lot of editorial work, even if promising for other reasons. There is already too much finshed, completely polished work that needs a berth. I've had editors of my own work that were more or less hands on/hands off and find both appealing for different reasons in terms of line edits or ordering considerations. Both are useful depending on what you need and have their benefits. Some writers feel more comfortable with an editor who can be kind of a final reader with suggestions on ordering and cutting poems. Some authors are sending things they consider finished and don't need anything more from me than to get to laying it out.
So really in the end, as a curator, you take what you like, what speaks to you, what seems important to you. The sort of work you want to define as your press aesthetic. And it does seem, over time, people know what to send my way. I used to get into really heated arguments with men about the logistics of running a feminist press, how certainly I was losing out on possibly publishing the "best" work out there by only accepting submissions from 50 percent of the population. But really, I am always highly suspicious of those presses and journals who keep throwing around that word "best." According to who? According to what? My thought immediately goes to the upper middle class, white, male standards that have only now began to crumble.
Granted we can usually agree on things that are bad (limericky rhymes and cliched overdoneness usually don't fare well), but there is a huge lack of consensus in the various corners of the poetry world as to what exactly is good depending on your personal aesthetics inclinations. And truly, if Rupi Kaur is selling millions of copies, obviously there is an audience for all sorts of versification..as an editor, you just need to go with your gut.
So maybe it's all we ever do, as so called "gatekeepers" (and there is another entry for another day about founding and starting presses and how important such things are in abolishing gates of any kind.) And really, so much of what the rest of the world deems "best" falls rather flat on me (stuff like Wes Anderson movies, red wine, jazz) So really, it's not surprising that my literary tastes run slightly askew..