How would you recomend making these?

[Chibi Kiku-chan]

Hiya! ^^
I'm trying to get an early start on cosplay for the year because there's an anime con (Kumoricon) that I wanna go to and not only would I be making my cosplay costumes, but probably a friends as well. (Maybe more than one friend)

What material would you sugest I use for these, as well as how would you sugest I make them?
On the Suzumiya Haruhi one, I think I might have a pattern that'd work for the skirt, but I'm a bit unsure on the top.

Links:
Asahina Mikuru
Suzumiya Haruhi - Bunny Girl (Not sure if this can be worn to conventions..)
http://home.sch.bme.hu/~chme/_pics/suzumiya_haruhi_cover_1.jpg
Lucky Star uniform  

[knitting_needle_ninja]

For the uniforms, most cosplayers use quilting fabric, because it is some of the most inexpensive that you will find at the fabric store. It's 100% cotton, or close to it, usually, so it's pretty easy to care for.

I would not recommend the bunny outfit simply because of practicality. That is not a comfortable enough outfit to want to wear all day, in long lines and crowded vending rooms.

For the Asahina Mikuru costume, I think you could probably get away with the cotton fabric for the skirt and apron, but you would need something with a touch of lycra or spandex for the top. This will also make it a little more forgiving so you're not going crazy trying to get the pattern exactly right.  

[Chibi Kiku-chan]

Ah ^^ Okies, thank you.
Mkay, bunny girl costume out, and one more question.
What is lycra?  

[Silver Mist]

Lycra is an elastic material thats often woven in with other fabrics. It can make things slick, but it mostly makes them stretchy. Its in most swimsuits and workout clothes. Spandex is the same thing.  

[wynter_myst]

Despite what anime/manga artists draw, school uniform tops don't exactly look like that. Which makes making them even more annoying...

This picture shows how a normal school uniform has the closure in front (you can use press buttons). Usually it's hidden by the ribbon (also attached using press button). It's much easier to put on this way than if you use a side zipper.
And the triangular piece of fabric that goes across the front is really just a triangular piece of fabric that is attached (with press buttons) to the inside of the front...
You can combine the collar to the top, or attach it separately. Press buttons are your friend. You can get as close to the seamless look with them.