User blog comment:Sannse/Choosing the Right Admins/@comment-452-20140730185125

One way I choose new admins is if they're often contacting existing admins to perform admin actions, then they probably need to be able to do those actions themselves. Specifically, if they're replacing a lot of images with better versions, I'll give them admin rights so they can delete the old files themselves.

Another thing I always take into consideration which is only briefly covered above, is whether they take part in discussions on forums and talk pages. It's all well and good for someone to have a thousand great edits in the main namespace, but admins should also be expected to take part in discussions. (Tagging active discussions helps.)

An extra point of advice I would add for anyone choosing new admins is to not be afraid to pick people who don't always agree with you. So long as everyone means well, and is willing to discuss the merits of their ideas, it's great to have different opinions, as it really helps work out what's "best" for the wiki.

Oh, and I also try to look out for people who are in different timezones, to help ensure there's always an admin awake somewhere in the world.