Yo! a little late to the party but welcome aboard! Looking solid so far, keep at it mate
Things that help that you've probably heard before for the line quality is to work as much as possible with the shoulder and using as much of the canvas as possible. for example you can zoom into things and use the entire canvas in digital (as opposed to paper where sometimes things are small and can't be changed) or you can work with all your canvas and then transform something big into a small portion of your drawing. Another thing that helps immensely in allowing my brain to make any curves or lines well is giving me limits before hand. Like with figures, blocking in sometimes I will put a point or very faint line on the top or bottom or literally a big weird geometric shape that englobes the entire figure, giving me a top and bottom limit, placing a wrist joint before making an arm etc, kind of like the idea of the line exercises, as you place points for beginning and ending, it's easier to then make a line from point A to point B
cheers!