It depends in whether I want to send it to someone in the local network or through the internet.

For local network:

I use miniserve ( https://github.com/svenstaro/miniserve ) which is just a simple http server. There are similar tools for when I want to share it from the smartphone.

Through the internet it really varies:

Sometimes it is Firefox send ( https://send.firefox.com/ )

For photos, I use a self hosted photo solution piwigo ( https://github.com/Piwigo/Piwigo )

In earlier days it has been a self hosted nextcloud ( https://github.com/nextcloud/server ) instance. I still use it when the files are getting too large for Firefox send.

I also tried the already mentioned wormhole but this works only with tec ppl.