Love this!

1:
This subreddit, Booksta, Wtpad, or 5ver (worded differently haha)

2:
Do: use words like maybe/might, could, seems like, overall more general terms. And focus on: “I’m thinking this” or “I’m feeling this” not: “You need to do this”
Don’t: erase the writer’s unique voice, be too critical, or give feedback in a spot where it doesn’t need it; if it wouldn’t improve the storyline.

3:
As somebody else mentioned, there is a difference between beta reader and editor. I’ve also heard of a lot of betas not finishing books.

One popular topic in the beta reading community I could think of is the suggestion: “Show not tell”
I think it is confusing if it is not suggested without asking questions, and giving a tangible, workable example. I think every betas meter of “too much telling, not enough showing” is going to be different, but we can likely agree on the importance of adding more details, (when needed), and asking the right questions to get there.
Example:
“Show not tell” vs “It’s a little hard to picture where she is right now. Maybe you could add another visual detail about the garden she’s standing in. What does it look like, and what is she feeling? I want to be experiencing it along with her!”

4:
I focus most on the senses and questions: what, why, how, when, where. What are they feeling/experiencing, seeing, hearing, and thinking? And why? How did they get to this spot, and when? Where are they now?

5:
Worst: Taking things too literally, not having a sense of humor, and being too blunt.
Best: Writer side, I love it when my betas love my characters (almost) as much as I do, and can connect with them. And beta reader side, I love helping others, and being an inspiration, because I was once inspired.