For people who feel they cannot leave a "good enough" comment on a piece of fic. A by no means exhaustive but hopefully helpful list.
1) MOST IMPORTANT: whatever you comment is good, even something as simple as "yay I loved this" is better than no comment. "I'm mad I can't kudos twice" "I really enjoyed this" "I was so excited to get the notification for this story" these are ALL GREAT COMMENTS, you might feel like they're "not good enough" but I assure you you're wrong for most writers, most of the time.
2) quote your favourite line(s) back at the author. if you then comment on the line(s), awesome, but having my writing quoted back at me with đ or đ or âĽď¸ = awesome awesome comment.
3) keysmashes make great comments. there are a handful of people I've met who don't appreciate a good adjfjsllfjfnjdjd on their fic, but in my experience they're wildly in the minority.
4) gif responses: code as follows
<img src="LINK-OF-IMAGE-HERE.GIF">
If the image is small you can also add in another piece of code which is
Make sure you keep the " in, they are important.
You can use a different percentage, but percentage rather than pixel size is best because then it adapts to the size of the device.
A gif is like the pictorial version of a keysmash: "I am not able to express my feelings in words, please have this gif of my Emotionsâ˘!"
5) where appropriate/true: "headcanon accepted"; having someone say they're adopting a specific thing of mine into their personal headcanon? That's good shit, folks.
6) this was so in character! again, don't lie about it, but if that was your reaction, that's an excellent review - I'm always delighted by these!
7) I can picture this happening in an episode! another one that is never stale.
If you leave a review with a combination of these things, you stand a genuine risk of your fanwriter crying and/or promising you their firstborn.
In conclusion: No question, any writer is going to be over the moon if you come and leave a long, in depth comment that details your reactions to specific bits of the story or compliments a specific aspect of our writing or our characterisation or our world building, those reviews are golden, they make my week/month/year. When someone comes along and writes a miniature essay in appreciation of my fic, I die of happiness. If you are able and willing to leave such a comment, your fic writer will be delighted. By all means, do it!
Just saying "adndndjksd i loved this đ thank you!" IS A GREAT REVIEW and honestly it's hard to find anyone who wouldn't have their day brightened. No matter how simple or inadequate it may seem, trust me, it is not.
@wolfiethewriter suggested one that's too good not to add to the original post: "how dare you hurt me like this" or variations thereupon is an excellent comment for Ze Angst đđź
Also for smut, "I had to close this because I'm in public" will make your writer very happy.
Another couple of excellent ones by @fanpersoningfox:
My personal favorite is just describing your physical reaction: "this made me smile" or "I'm in physical pain reading this OMG" or describing the circumstances you're reading the fic in: "I'm on public transport, why am I reading pwp on public transport, I should know better" or "it's 3am and I have to get up in four hours but holy shit"
@whatafuckingdumbass says they comment like a drunk girl complimenting another drunk girl in the bathroom, and honestly? That sounds like an amazing comment philosophy, if in doubt, do that đđź