you definitely have a lot of new and refreshing ideas!
-it's all about the presentation. I know croquis' are always a designer's personal stylistic choice, but I'd say look at some examples to perfect the anatomy.
-for collections, it's all about keeping everything consistent. Some of your croquis' have different body proportions which distracts from the design of the clothing! For an overall collection, try to have a more cohesive look (see 's comments about silhouettes and colors)
you can produce really good work if you work out these kinks! other than that, really nice job! Keep working hard and improving!
oh! the fashion model sketch. the way they are drawn differs from person to person. i draw mine ~9 heads tall, really long legs, half a face, etc, etc.. you can check out my gallery to see what exactly im talking about
here's a little trick i learned. You print out the template/croquis/etc..., and then grab a sheet of normal lined paper. Put the lined paper over the template and hold it up to a window that light shines through. You should be able to trace the croquis!! After a few months of doing this, you eventually get a hang of basic body proportions, whereas then you can take artistic license and create your croquis to your liking. so, it doesn't have to be 100% anatomically correct to the human body, but the basic proportions have to still be there, if that makes any sense. If you ever need help with anything, feel free to leave me a comment on my profile!
You have some great ideas, the second outfit is my favourite as well! It works best if you look at the silhouette and the colours, sometimes it's good to add some contrasts. I like that you already thought about what kind of fabric could be used for the blouse. But I think your outfits don't work well together yet, if you want to do more collections in the future, try to do multiple sketches and choose the ones that are best fitting. It's difficult to learn seeing that, but if you're interested, look at some fashion shows, they teach you a lot and it also is VERY inspiring! Keep it up, I love looking at whole collections and would love to see more!