1) the very first rough, super messy, but the basic poses are fixed
2) the sketch is refine a bit to be more readable
3) it's almost a lineart, but still too messy, so it's more a "very clean sketch"
4) the flat colors of the different characters
5) I put a layer on "multiply" mode with kind of purple on the whole picture
6) I erase the part where I will put some light
7) add more shadows! and blend everything
8) new layer in "overlay" mode for the light
9) merge again!
10) add some colors more warm for a lovely vibes + a bit high lights to make it more vibrant
11) last detail and I'm done!
This colored sketch was done in ~2 hours.
I thing for the future step by step, I will try to add the time for each part!