Hey Leo, nice to see that you try to push and also bend your cylinders.
I think its a good idea that your draw through the the form of the cylinders and then erase what you don't need, just trying to draw half the ellipse is quite challenging in itself and something that you can try do when your get a little better hand coordination.
Also it is very useful to use the end of your pen and then try to match the direction of that limb to observe the degree of the ellipse.