A lot of people who know me know I like to read, I read a lot of different things, and I read quickly. I also like to post about what I read on Twitter or my Goodreads profile.
The problem is, people seem to mistake my ability to read quickly and the fact that I have read things in a number of genres (although I do have preferences, but reading fast means I just get through more books than a lot of people, so I have time to read from a greater variety of genres and sources) for the idea that I will read just about anything tossed my way.
This means I get well meaning people I know asking me to read their (often) unpublished work, or their self-published work and for me to give them my opinion. I've realized this often means they basically want to use me as a free editing service. This isn't something I'm interested in doing, and I don't want to get into a place where if I do read their work, where they expect me to give them free advice on how to make it better, or what have you. I also do have some sort of mental selection process - so I might not even be interested in their book at all.
I've tried outright refusal by just telling them I won't read it, which usually ends up with them nagging me because they feel I should as a show of friendship, or causing fights about how I don't value the time and effort they have made in writing the work. I've tried stating it's not of interest to me, which only works if it isn't in a genre I actively read - otherwise, they'll push back. I've tried saying I don't have time, but since I read so many other things (and this is visible to anyone who sees my Goodreads updates), they get mad that I have time for other books, but not theirs.
I've also tried limiting myself to only reading the first chapter or so of something, to see how I feel about it, or to placate someone. This usually ends up in people telling me "well, you started, might as well finish, right?" or claiming I didn't get to the "good bits" if I say it's not to my liking.
I'm trying to find a way I can avoid reading things that I have no interest in (either because the book isn't appealing or I don't want to get into the free editing trap) without causing ridiculous rifts in my friendships.
I don't work in any sort of writing/editing/publishing related field (I currently work in tech support), I don't have a lot of people who follow me on GoodReads or Twitter because of my reviews or anything, and I don't get paid for anything I read or maybe review. When I do write reviews on Goodreads, it's often just like the star rating and maybe a sentence or two if something really struck me (good or bad). On Twitter, I usually just tweet when I particularly like a book or a particular passage really struck me, but again, I don't have a lot of followers and I am not really intending to be like a serious contender in the book review world, I just share about things I like in the books I read the same way I'd share on Twitter about movies I liked or random cute animals I've seen.
Is there some sort of tactful approach I could use here, beyond what I've already tried?