I'm going to keep this short. I currently have a free art shop in Tier 4 and I am wondering if there is anything in particular I should be working on to try to move up to Tier 3.

Oh you could easily move up to tier 3! I'm in love :0

You should definitely start charging!! You've got a great handle on lighting and blending horses into their environment. My main criticism would be your muscling/body prep. You have a lot of lines that don't necessarily correspond with actual anatomical features so I would recommend finding some solid anatomical references and maybe doing a little bit of studying ;D

Easily tier 3 though! ~80-90k per piece

@[Gem]

Do you think what I have done with this main horse is better with the muscling and body prep? The piece is obviously far from finished lol

Something that I find very helpful is blurring the background. It can help draw the attention to the horse and makes the peice look a little more finished.

I'd absolutely move up a tier!

I agree with gem on pricing, 80-90k mark is right.

something that really improved your art and fast is your understanding of lighting (I abuse this by making very dramatically lit pieces 24/7). Good shadow placement and well done highlights are the biggest cheat code to having great art. Try studying the stock images you use, figure out where that light is coming from, and how harsh it is between pieces to get an idea of how light effects object. Buckleighh is a brilliant provider for this as the images are always very good quality and well lit!