How do you know a good beta reader from a okay beta reader when you can't tell yourself.
Only experience or word of mouth will tell you that. And even then, word of mouth can be deceiving, as one beta-reader can be perfect for one writer and impossible to work with for another author.
As an author, you might notice if someone regularly comments in your comments folder and gives you constructive criticism that does make you change things in the story; if it's the case, why not ask that person if they have time and would be interested in beta-reading for you?
As a beta-reader, you probably read a lot of things on the archive and on the MBs, and you develop a certain taste for this or that type of story, or for a few authors' writing style. If an author whose work you like interests you and you notice they're asking for a BR, why not offer your help and see if they're interested in working with you?
The point is to find beta-readers who correspond to your writing style, so that they can truly help you with the writing of your story. The partnership must work perfectly, or else both you and your BR will be unhappy and the story won't be any better in the end.
Kaethel
