Perhaps you can make use of my tutorial hoard!
I uh.... collect tutorials on pinterest and have amassed quite a collection here on all sorts of things like anatomy, faces and colour in a variety of styles (since most styles have a lot of crossover in terms of the basics.
Right now, your line quality is good, so that's a good start, nice and neat, but the main area you need to work on is using your lines to create a sense of mass and volume so that the figures feel like they're three dimensional.
I wouldn't recommend tracing for you, because tracing is more useful for people with poor pen control, whose lines aren't going where they want, and your lines are actually pretty clean and confident. The thing I would prescribe you is doing lots of quick anatomical sketches. Get a sketchpad or have a big digital canvas and try to do a bunch of anatomical sketches of people in different poses at least a couple of times a week. Don't worry about being messy; you don't have to show anyone your sketches (you can if you want though). The people can be clothed, unclothed or a mixture. You can draw from photos or life if you like, or try to draw a character in the style of an artist you like but in a new pose by looking at many drawings of that character from different angles for proportion reference. Doing a mixture is good too!