Recommended Reads can be awarded by any of the Story Mods, either at the time a story is verified and posted or at a later date. They're mostly (but not always) awarded at the time the story is verified. However, it's not uncommon for a different Mod to the one who verified the story to award one after reading it some time after. There aren't any hard and fast rules as to why a Mod would award an RR, but pretty much flawless grammar and punctuation, plus a strong plot and good well rounded characters would be a good start.
Editor's Picks require the nomination of the story by a Mod to a special panel of some the best author's on the site. That Panel then reads and votes on the story.
Some of the posts towards the end of this thread may also be helpful to you....
https://www.lushstories.com/forum/yaf_postsm2016872_Lush39s-high-standards.aspx#2016872



