depending on what style of cape you want, reeve or routh or cain.
from what i understand the basic principle is the same, you just pick a different attachment method.
i made a routh cape and all i did was go to a fabric store and buy some red fabric, standard is about 60 inches wide, which is about 150cm, so find a fabric 150 cms wide and get 3 meters of it.
this will give you a big flowing cape with no seams.
lay it out on the floor, and now decide how long you want it to be, i wanted it down to mid calf height, so 4 feet, so take a fabric tape measure and pin the end of it to the center point of your fabric along the 3 meter length
now using the center point and the tape, measure out your desired cape length and draw a big semi circle, so that the radius of your semi circle is your desired cape length, now cut that out and you should have a big half circle shape. now using that same center point, measure out how big you want the neck opening, and draw another semi circle, this will now be a piece you cut out so the cape fits nicely to your neck.
now take some of your excess fabric, and make another small semi circle with it, doesnt have to be much, just enough to reach your shoulder blades. cut out a section for your neck again
now you sew these two pieces together, i find it best to put the outside (the part you want showing) of the cape with the matching side of the shoulder section, and sew along the inside of that along the section you cut out for your neck, now once you turn the cape back to show the outside, the colours will match and the seam will be on the inside hidden away from sight, now all you do is attach some velco on the little shoulder section and tuck it in the neck of your suit, where it can velcro to an undershirt, under armour or something works great for this, that way the velcro wont be pulling on your suit and you dont have any straps sitting uncomfortably under your arms.
sorry for the long post, i can send you pics of mine if you want? pm me
as for the reeve method, it is simply a piece of fabric cut in the shape of a slice of a pie, again with a shoulder section attached like the routh cape and them you add a strap to the top of it and it goes round your shoulders like a school bag, then tied behind your back, here is a very in depth tutorial, which will explain the shoulder section of the capes
SUPERMAN COSTUME HOW TO DIY: S-SHIELD, CAPE, BOOTS AND BELT (MERGED!) in The Library of Do It Yourself! Forum
depending on the fabric you wont have to worry about hemming, i got some synthetic satin for my cape, had a nice matt red colour on the outside and i put the shiny side as the inside of my cape, so there is something to catch the eye when it moves
hope it helps
