Practice is always the key to remove yourself from plateuing.
I myself feel like being plateued from time to time, but I look back my sketchbook I did year ago: I discovered myself I have improved from that year till today.
I admire especially your hand sketches, they are smoother to see (than what I do, hehe)
On two images, you're getting hand of the artist style of sketching, really handy for practicing and starting out!
Keep movin
