I keep seeing posts and comments about how "it's so hard to leave comments on a fic" because either readers don't know what to say, or it's just too much emotional/mental work to come up with something.
So! Here's a quick cheat sheet. Feel free to copy+paste these to make commenting and supporting/encouraging fic authors easy and painless! (also, consider: you can leave as a comment any of the keysmashing you'd do in tumblr tags. Go nuts.)
Most of these can also be used on videos, art, and anywhere else you might leave feedback on a creative project.
I loved this chapter! Thanks for the update
I am up past my bedtime reading this.
I'm reading this at work/on the train/in class/at a party and I'm loving it
So good! Can't wait for the next chapter!
Was so excited to get the notification for this!
I enjoy/enjoyed this fic so much.
I'm sending this to a friend!
Biting this. Eating it. Devouring, even.
I loved when [character] [did thing]
I loved the part when [thing happened]
[literally just copy+pasting a line you like and adding !!!!!!!!! to it]
My favorite part was [the part with the thing]
I love how you write [descriptions/dialog/specific person/etc]
Oh no, [character name]!!
Point out a line you liked and what it made you think/how it made you react
Ask a question like, "Is Hardened Detective Man's mother still alive in this AU?" or "Does Brave Space Princess know about the [macguffin mentioned in chapter 2]?" or "Who's your favorite character to write in this fic?"
ask a rhetorical question of the characters, like: "Lovable High School Character! Do you have any idea what you're doing???" or "Dinosaur Researcher, are you aware there's a whole series of movies about why this is a bad idea?" or "Dark Vigilante Father Figure, do you even see what your adoptive acrobat son is trying to tell you?"
Address a statement to the characters (similar to above)
Tell the author how you found their fic
Tell them you're subscribed and you get excited whenever they upload
Comment that you can't wait to see how [story element] works out.
Commenting is the best way you can encourage a fic writer and inspire new content. And comments aren't book reviews (or at least, they don't have to be. We do love those though lol) -- they don't have to be long and complex. Keysmashes and emojis and one-sentence reactions are MORE than awesome!
If you don't have the energy or time to comment (and remember, even a !!!!!!!! is a great comment), at LEAST leave a kudos and consider saving a link to the fic to come back and comment later.
Now go forth! Support writers! Be a part of a healthy fandom ecosystem!