These are some really cool drawings you have! Love the smooth and thick lineart, I can only presume you use vectors or pencil tools to obtain their clean look. Your first pic also shows that you're capable of properly coloring and shading a picture as well, and not just leaving the badass lineart as it is. The depth and relative proportions in the Glacia picture does seem a bit off though, as Glacia herself seems to be quite tall give her position and relative size to the other Pokemon. The Glaceon further back could also be blended further into the background unless the air is crystal clear, or at the very least be slightly blurred or not as refined as the other creatures since you won't be able to see as much at that distance.
As for things to work further on, I suppose you could use a change in setting I suppose. You seem to be digging the "trainer posing with their Pokemon" approach, which while awesome, can grow old fairly fast, so showing them in other settings doing everyday life activities or perhaps even engaged in battle could be a next goal.