Hugh Lashbrooke

Sick of adding a image to your post content then also setting it as the featured image in a separate action? Of course you are!
This plugin solves this problem by adding a new button alongside the “Insert into post” button in the media manager modal. When clicked, this button will insert your selected media and then, if you have selected an image, set that image as the post’s featured image.
It is possible to select multiple media items to insert, so this plugin will set the last image in the selected set as the featured image. The button will appear in the media manager modal for all post types.
This plugin works with WordPress 5.0+, but it will only work with Classic block or in the Classic Editor. It does not currently work with the Image block (or any other similar ones).
Want to contribute? <a href="https://github.com/hlashbrooke/Instant-Featured-Image" rel="nofollow ugc">Fork the GitHub repository</a>.
Got some great ideas? <a href="https://wordpress.org/support/plugin/instant-featured-image" rel="ugc">Post on the support forum</a>.

Instant Featured Image

Set an image as the featured image at the same time as you insert it into the post content.

sewpafly

To meet the needs of themes where the post-thumbnails have random and capricious sizes (which causes wordpress to crop images simply from the middle (either chopping off the top and bottom or chopping off the sides), this plugin attempts to give the users an interface to manually fix those thumbnail and random images.

Post Thumbnail Editor

Does not work

Fed up with the lack of automated tools to properly crop and scale post thumbnails? Maybe this plugin can help.

Instant Featured Image vs Post Thumbnail Editor