HEART STOCKINGS
Design : Simple, straightforward. Could consider to add more designs to it.
Shape : Stockings itself is a following shape, smart to choose the easy one to start with.
Shade : here comes the trouble. DX
1. You have a lot of dithering for such a small pixel space. Instead of dithering, small pixels are better to clump together in larger shape than dither it, it makes the stocking looks noisy.
2. You use the wrong shade to shade the lines. The relativity of the shades should be as close as possible. eg. shade 5 next to 4, 4 in between 3 and 5... and so on. Better don't jump shade if you are going for a matte(non gloss) surface.
3. You can consider shading a little for the heart. Though it will be too minute to see for now. Looking at the white stocking shade, if the heart falls on darker shade, the heart can use the darker shade.


LEOPARD LINGERIE
Design : Simple, pattern dominated. Though... is leopard that kinda colour? DX You can consider a single slant strap to it. Leopard means speed, assymetry could look better? or double slant strap. As the slant strap could hint the running leopard's tail/shadow...
Shape : For the bra, I think the under piece below the armpit is too thick. As for the Undie, I suggest you layer an existing Menewsha undie and check your curves whether it is centre, I kind of think it is slanted a bit. Generally, tight fitted shape is hard to go wrong. Smart move to start with those type of clothing.
Shade : Pattern wise, leopard pattern are suppose to be black circle with the centre orange brown. What I see now are spots. DX
Bra's outline need some shading, your undie outline is shaded okay.

CONCLUSION
Good starting point. You have a fair understanding of shading, but may overdo in dithering for shading. You could improved more if you observed and study the object more. I would suggest not to delve into difficult pattern at the start, master the shading and shape first, as pattern is a compilation skills of both.

My CSI is not graphical, muaha! XD