Hello there Mystery. In the end our ideas are a mix of past knowledges we patch up from different sources. New ideas are often old ideas with a little (or a lot of) tweakings. Just make sure you have a keyword, a source of inspiration, and asks yourself questions.
I usually makes sure I find a keyword first, then even a meme will be a source of inspiration. With a keyword, it's easier to fall down the rabbit hole of venturing the 12th page of google about a certain person's biography or bizzare technology you've never heard of.
If you get inspiration from reading/watching, maybe you could try new authors or movie genres? If you don't feel like sticking to a long one maybe try short films or animations in YouTube, or read short stories on writing sites/apps. If you want to try other mediums, what about prompts? Do writing prompts serve you any good? Or maybe the news (real life events)?
I personally draw inspirations from visual stimulation (pictures, gifs, muted videos). I tend to randomly try giving stories to places, objects, or living creatures by looking at the details of the pictures. So you can try looking up pictures with the vibe you don't normally search. Say, if your RP usually entails serious, action, sci-fi atmosphere, maybe look for bright fantasy scenery, modern business districts, indigenous people photographies, etc. If you don't want to stray too far from a genre, look for variations within the genre that your haven't tried. Like, in scifi you always do high-tech cyberpunk but never tried historical-vibed steampunk, or never tried combining sci-fi with magic and the elven world.
The 'browsing a keyword' thing is just to kickstart the gears, so it's okay if your idea started off heavily similar to a story I've read/watch. When I notice similarities (with other stories) in the direction my imagination is going, I tweak it by asking "if things didn't go that way, what possible ways would it have gone like?". Sometimes it's like a butterfly effect, one thing leads to another and gets real crazy (wholeass world building). Sometimes my brain settles for a light-hearted, predictable story just for the fun of playing it. Sometimes I got nothing interesting until I'm hungry from thinking. Basically, I daydream a lot (if not too much) and usually I end up indulging myself in a made up plot/character before I know it.
(Also, I wonder what you mean by 'not difficult'.)
