I write fanfiction. A lot.
Lately, we've been watching CW's four superhero shows - the "arrowverse" as I've heard it called - and I've been finding myself more and more annoyed at the TV shows. There are multiple, reoccurring things that I have found myself shouting at the TV for, and these are the most annoying of them.
This is, however, a list fun things that fans like when accompanied by good, likable characters with a thought-out compelling plot that takes place in a well-built world.
As a fanfiction writer, I see fan creations as a gateway to original works. Experimenting with fanfiction gives the writer experience with characterization, dialogue, sticking to previously established rules, grammar, formatting, title-giving, and summarizing. Fan art is a lot like this as well. Using fan art, the artist can learn about proportions, colors, facial expressions, and much more. Someone who can't draw can start with fan art, and slowly build up to the more original pieces, until they are doing their own work.