1. Any recommendation for what cloth should I use (the black and gold part on her skirt and vest)
--Twill would be good. A simple cotton is fine. Heck even vinyl works..I've seen all sorts work for this. You just have to know how to use what you are making it with..Like if you have never sewn vinyl, then go for a cotton..For the gold, get gold bias tape. You can also make the chest design with gold rope. That's what my friend did for hers.
2. What kind of cloth can I also use to make this black transparent inner shirt she has?
--Not sure why that reference HAS that..Is this a newer version or something? Because her in this outfit I've never seen any with that under part..If this is a new version then I understand, and you could use a thin mesh or like mentioned, organza.
However, if you are not sure if this is a new version, maybe check all of her defaults (usually called version 1 through whatever, like Miku V2 or Miku V3 (versions 2 and 3) and see if it actually comes up..Because I know the original in the exact outfit does not have that, and this looks like a fanart anyway..
3. What kind of paint can I use to tattoo the number on my shoulder?
--This is totally up to you..You can do Henna, sharpie, or any other method of drawing on yourself..You COULD use body paint, but I don't know anything about that..I use sharpies..
4. What kind of paint can I use to make her arm warmer details?
--Depends. If you use vinyl like my friend did, she used vinyl paints..If you use normal fabric, use fabric paints..
5. How can I make her belt? Any tutorial for belt that has many triangles?
--Paint. This is literally the only way outside of hand making a belt..Use belts in one of the 2 colors (my friend had brownish black belts) then use paint in the other color and paint it.
6. Can I use craft foam to make her brass thingy on her chest?
--I covered this above, but if you want, yea. Just cut out a picture of it on foam.
7. Can boot cover work with the boots that she is wearing?
Yes they can.
Are made over heels.
You should use gold fabric, and maybe something thick..Maybe vinyl..
I used this tutorial:
Then instead of the fabric going under the foot where you will be stepping on it, I just hot glue it to the sides above the sole. Then you just make the holes, preferably using a grommet punch with the 2 sided grommets (sometimes called eyelets) and make those your lace holes.