These are fantastic. I can only compare them to my own work and the same reference I have used. I don't really know enough to offer advice on how to escape a plateau - however, I do want to just encourage you to keep working at it.
These are excellent, you have absolutely captured the form and essences of the references. Just keep working at it, the hours stack.
I'm extremely new to illustration, I have maybe 40 hours in all things considered. I'm nothing compared to most everyone here, so I don't have that much real advice to give. However, one I for sure have discovered is: eat something before you start, especially if you're still deep in the learning fundamentals phase.
Your brain is rapidly rewiring itself trying to acquire the new skill - especially in the beginning. It needs more energy for like hours 0 - 50, than it does for hours 200+, for example. The friction and frustration you feel as you work will not be as bad with a little food. Literally can be a snack.
I hope someone out there finds this useful, It has helped me. Good drawing everyone.
(Note: For some people it might be the reverse. People are different, and so are their brains and metabolism.)
I think these are really solid for just a few weeks. Much better than mine. I think you just gotta bang out more hours.
