My old workflow (Nf4) but enhanced with proper groups and flux Q8 (nf4 node still present but bypassed u can connect if u still use it) with nf4 change flux guidance from 4 to 3.5, it changes render times a lot for me

but i recommend Q8 and change the values for the resolution if it takes too long

custom node https://github.com/city96/ComfyUI-GGUF (install via manager, simpler)

go to ComfyUI/custom_nodes/ComfyUI-GGUF

   .\python_embeded\python.exe -s -m pip install -r .\ComfyUI\custom_nodes\ComfyUI-GGUF\requirements.txt

(i think the manager does this by itself, but i'm noob so have it)

Get the Q8 gguf and put in UNET folder

https://huggingface.co/city96/FLUX.1-dev-gguf/blob/main/flux1-dev-Q8_0.gguf

As always, ignore the cursed prompts, fbi is knocking rn...

Photos done with Q8

Sorry if errors, sill a noob to this