A1111 img2img inpaint works pretty well, if you get a checkpoint that matches the style you're inpainting. Civitai [0] can be a good resource here, and it's not just for perverts.. I swear! ;)

[0] https://civitai.com/articles/161/basic-inpainting-guide

For Automatic1111, the easiest fuckups are messing with the scale and not using a model that can handle inpainting. Then there are the unintuitive "fill" radio buttons that I don't really understand myself (what they do is obvious; why you'd use them is not).

InvokeAI has a much friendlier UI, inpainting is easier, and the platform is more stable, but is lightyears behind in plugins and functionality.