I always had trouble going through the thumbnails.
usually they are low-res or just too small for me to see anything.

I found a userscript that's supposed to help, but it stopped working and the user's twitter got deleted (rooshoes).

So, I adjusted it to made it work again.
Per default it creates 200px wide thumbs, increases resolution, plays gif as thumbs and makes webm playable in the thumbnail.

In most cases thumbs are replaced by the /sample/ images if possible.

https://greasyfork.org/en/scripts/392572-e621-thumbnail-enhancer

Oh, this is kickass, thanks for sharing.

I would love to see this updated for the new site

Seems the new site doesn't use the same css conventions as before, is there a possibility to adapt this plugin? Have tried working on the original script but was unsuccesful so far