Tried to post here last night, but my wifi simply refuses to let me on here anymore..I hate technology so much....
For the straps and belts you will want a leathery material. Leather is what it's suppose to be, but not everyone can afford the amount you will need. You will need a lot. So go with vinyl. I used thinner stuff, but used interfacing and heavy fabric backing to make mine stiffer.
You will need to measure your waist. Put the measure tape arounf the natural waist line. This will be right around the belly button then all the way around you and back to the starting place. Go about 2-3in overapping and that's the measurement. Figure out the halfway and that will be the center of the belt. You will probably want to use newspaper or something to make a pattern. Fold the pattern materials in half so now it's half the length you need. Draw half of the belt then cut it out on both folded parts and unfold. You should now have a full belt. Trace it onto the vinyl and cut it out. If you want to you can add straps to the back or just really strong thick velcro. The second one is easier..Then you will sew on 3 loops. 2 will be in the front and one will be on one of the far ends that will be behind your back. Here's my cloud one so you can see what I mean:
Now you will need to make the emblem. I used this as a picture to base the Crisis coe one I made for my friend's Sephiroth cosplay:
Take your pattern paper and trace the belt on it you cut out earlier. Then draw this design on the pattern paper so you can size it up correctly. Then cut out all the pieces of the design (notice it has areas of the design that are mostly squares and such, they are not connected..Cut THOSE out). Then, making sure to keep all the pieces in the right order, cut them out of the vinyl. You will will need e6000 and you can glue the cut outs to the belt where they go. It worked just fine on the one I made. If you want to do it the hard way, you can embroider the design on, but this is faster then that..
Now the straps.
For these, notice there are skinny straps, then thick straps..We will call them as such. cut out 2 long strips They will be too long on you. You are going to put them through the front loops and over the back make sure they are fairly long. Then cut out the thick parts. cut out a top and bottom for each. Make sure the tops are the same and the bottoms are the same. The backsides of the tops and bottoms will touch, so they have to match that way. Then, put the bottom piece on your shoulder where it will be sitting, then make the skinny strap go over it where it will sit and loop it through the belt so you can figure out where it needs to be. You can see in the straps that the loop goes in and folds forward and snaps to hold it in place. Simulate this by holding it in the right area. Have a friend or someone pin the skinny to the thick. Sew in place repeat for the other side. For the loop part you will notice the back of the vinyl shows. You can remedy this by making really short straps that you sew back to back just a little past where it folds up. Then you put snap fastners on and use that to hold them on. Anyway, then you sew the top pieces on over the other parts so you can't see the skinny straps anymore. Sew around the edges. Then have a friend pin the straps where they meet just under the shoulder blades in the center. Pin and sew them together where they make a 45 degree angle (looks like a "V" shape). cut off the excess vinyl from the ends. Take one of the cut off pieces and sew it to the "V" shape making it a "Y" shape on your back. This straight down strap will connect to the back loop. Do the same as you did for the front ones. Then take whatever material you want (someone I know used a magnet and had metal in thair sword to make it slip to their back) and make a circular shape that you will use to cover up the area you just sewed up to make the "Y" shape.
On the armor, the easiest way is paper mache on a balloon, gesso sand then paint, but you can look up whatever method you want. Attaching them there are many ways. I used parachute clips that I got connected to the paperclay I used for my armor, then sewed the other ends to the straps..But there are tons of ways.
Hope this helps