Hello and good afternoon, Aitorsio. I'm Polyvios. Say, I really love how quick and slicker how all of your 1-minute figures are, and how much of a greatest job you're doing with all of the fundamentals of drawing with as fewest lines as possible. Way to go!
Question: Are these for your portfolio? What kind of portfolio is it? Is it for drawn animation or whatever? So that you could have a specific portfolio.
My bigger critique is that some of the poses, particularly the one standing with the legs spread out more apart is not looking or seeming flexible and plastic enough to me. Would you care to free up your non-dominant hand with 30 minutes of 30 second pure contour drawings of nude and non-nudes? (60 blind contours) The reason why is because you'd be able to get more out of your hand-eye coordination, and to get your hands in movement.
For further info, be sure to look up the Betty Edwards books on our Amazon pages, not to mention the Walt Stanchfield books. All in all, go with what works best for you concretely. Cheers to you, and I hope these tips've helped you out by a longer shot.