Hello, my name is Jessica. I am new to designing clothes. I’ve been designing for two months. I would love to receive some feedbacks or tips to help me improve.
This is my first clothing design, made in the early of July.
This was my second clothing design, made in the early August.
This was my latest clothing design, made right after my second one.
These designs were made using paint.net, please tell me how it looks! 
The design itself is really good, the colors and the linework are spot on (I especially like the shoes in the first one.) Only suggestions I could give is to have the skin-part be transparent so that the player’s skin shows through (you might have that already and just colored it for the display but I can’t tell), and lastly I would make the shading a bit more pronounced, except on the last example it’s kind of difficult to see.
Hope this helps!
The player’s skin is just for display. Thank you for your feedback. 
Third one is has good shading. Make sure you are not using someone else’s shading template. Add highlights and shadows on the first two. Also avoid straight lines as they are boring. Make them a bit curved.
Great job with your clothing! A few suggestions, the first 2 designs look a little flat. I would try to add some kind of shading or texturing to them. I would also try to make the skin transparent (unless they were colored just for the pictures); this would help increase sales due to it being more customizable. I love the shoes in the first design, you did an amazing job on them. On the second design, I would try to add a border (or make it more prominent if there is one) to make it look less blocky. Keep up the good work and I look forward to seeing more!