Here's what I do. I use Webs.com it's a website builder. I upload my photos there onto the file uploader. I'll do a tutorial for fopks to learn such a method. Once uploaded I right click the image and open new tab. It leads to a image url jpg type. Meaning the image file needs to be turned into a image link url ending in jpg or png.

You can do the same from any web server host, and especially if you own your very own server. Another way to test it out or to post photos here is from a public domain like Pixabay.com

There all you need to do is visit the image web page you wish to utilize. Then right click that image. Open in new tab and once it opens, copy the url aka web address.

These two methods are similar in how you'll need to copy and paste the image link url into the Steemit editor. Markdown is automatic so no need for any html unless you wish to center the photo.