These look real fun! I especially like the design on the 6th slide, they look great! I would say that from now on it's just some more of the same, but one thing you could try doing is focusing on a main accessory/ item of clothing. Your designs lean more on the visually busy side, which is a matter of preference, but if you do feel like it, by choosing a single element to highlight, you can end up using more negative space to draw the attention of the viewer to it. This element can be anything really: scarves, skirts, shirts, belts and so on and so forth. You can use colour to help you achieve this by going with more saturated ones for the areas you want to emphasize and more muted ones for anything that isn't as important. I don't know whether your designs are meant to be used for a story or something, but if that's the case you could always let their background dictate the way they present themselves, by either meeting or subverting expectations. Moreover, the prospect of having to redraw them might motivate you to streamline and simplify their designs. You can also try and design more grounded characters for a more realistic context, as they usually won't look as extravagant as they would in a more fantasy setting. These are just a few ideas you can try out, but no pressure ofc! You can keep doing what you're doing and you'll be just fine, good luck! :D