@Charlie-Eve-Ryan Well done you on completing this - great job! I agree with @thirdeyeh that if you were trying to improve on this, I would have a real go at trying to mimic the oil brush strokes and the way the colours smoosh into one another...if I look closely at your piece, I can see a distinctive little grain that repeats a lot. This is nitpicky though (has to be, at this level!) and it's very inspiring - so much so, I've started a master copy of one of my favourite illustrators too 🙂
By the way.. I know you can make your own brushes, but in case you feel like treating yourself, Kyle brought out an impasto brush set a couple of months or so ago...haven't got them but they look good. https://www.kylebrush.com/#brushes ...I've tried a couple of the oil ones from the Megapack which were nice too. But yeah of course you could save the cash and make your own unique bristle type brush. Or experiment with blenders/smudging and so on (something I'd like to try more of too..) Anyway it's been great to see your process here 🙂