enzobolev: I don't understand how to approach seki problems. Unlike other problems at the same kyu level, they seem to require thinking much further ahead at all the possible combinations and I end up forgetting which cases I have already imagined
d4rkm4tter: It is eye shape knowledge that you need to acquire. I give you one link about eye shape at senseis library https://senseis.xmp.net/?Eyeshapes but I recommend you to spend 30-60 minutes on that website. You can go from link to link like in other wikis. Other interesting starting points are: Killing shapes, Seki and corner shapes.
Thank you! This is exactly what I was missing