Advice/Recommendations in Regards to Image Rendering and Prompts

[G-Rated-Caucasian]

So now that this Program is beginning to blow up and people are beginning to generate art with it, I want to know what is the best strategy/technique for taking a per-existent Image, and converting it to the style of another artist. i.e. taking a random photo I took in a camera, putting it in img2img to turn it into something like a Rembrandt painting or something of that sort. I think you guys get the gist of what I am asking lol.

[G-Rated-Caucasian]

Like how are people pulling off pics like this?

[G-Rated-Caucasian]

to follow-up if you guys know any plugins that could help with this that would be fine too.