@123mine123 That horse decorative study look solid (If you don't add the gritty stuff since it looks more brand new compare to the reference). Understanding the skeleton of the forearm and imagining how the meat wraps around it can help. I keep forgetting what those heads plane thingy called. Try filling the canvas with the darkest color available in the reference and work up the light colors from there.
@LuisEC You should definitely try circling the ones you mess up on, look for a possible reference for those and redo them when you have the time.
@Kalicia I think you forgot to attach the picture
@CherryzBomber Try finding a pdf file online called Burne Hogarth - Drawing Dynamic Hands. It explain the skeleton of the hand, veins, direction, structure, simplifying, and so forth.