Try the new Flux.1 Fill outpaint for improved and simpler outpainting.

Resource saving outpainting where you can choose the style weight of your uploaded image.

How to use

Of course, upload your image. Scale down your image to the desired size (yes, only scale down, it won't upscale), then pad each side at your will. A default inpainting model is already selected.
I'd suggest you to scale down to 1024 pixels if you are going to extend only horizontally or vertically, and to 768 or lower if you are going to do both. Being based on SDXL you might get optimal results when the sum of each side of the starting image and the respective paddings reaches 1024 or 1152, but feel free to experiment.
The starting image influence setting will indeed influence how much the outpainted area is going to look similar to the starting image itself, in terms of style. A setting of 0.4 or 0.5 is usually enough, but again, feel free to experiment.

I've realized this tool for myself and my outpainting needs in the first place, but maybe the community might find it useful as well, therefore I make it available to everyone. Hope you get great results with it.

OUTPAINT

Image Extender

Outpainting

Flux.1 Fill outpaint

Flux.1-Fill-Outpaint