When I beta read, I mostly correct bad grammar and I'll leave you notes inside your work telling you what I suggest changing. I leave most changes up to you, such as OOCness, making it flow better, word choice, ect. I suppose I like to show you mistakes you're making so you do not make them again.

Action, making sure things flow correctly, grammar, run-ons, spelling, capitalization, fairly good with punctuation. Character development, drama, dialog (especially dialog, just read my stuff in the role-playing RPG Heroes, Villains, and Scoundrels, or its sequel Tyrants, Rebels, and Spies).

Romance, and occasionally I'll skim over small errors like a missed comma here or there. Also, I'll sometimes lose focus if the story does not interest me enough to actually read it.

I will beta read only things in fandoms that I know of and write about as well, that way I know what I'm doing when I tell someone is OOC or something.
The following are the only types of fics I will beta read:
1. Star Wars 2. Alias 3. Harry Potter 4. Xena: Warrior Princess 5. Pirates of the Caribbean 6. X-Men moives

Anything other then my preferred types. I'm have a closed mind in this area, I'm not going to pretend I know anything about Naruto and beta read a fic of it. I don't know who is and who is not in character, wont be able to relate it to anything, ect.

Tv Alias Book Harry Potter

Movie Pirates of the Caribbean Movie Star Wars

Movie X-Men: The Movie Tv Xena: Warrior Princess

General Humor Drama

Adventure Parody Angst

Supernatural Suspense Sci-Fi

Fantasy Tragedy