The pointy sleeves on Professor McGonagall's dress robes

So to start with I took my sleeve sloper pattern (see my tutorial on how to do your own!) and raised the sleeve head by four inches to give me a point of 2inches when the top is folded over, the pattern was only used to the elbow line.  You can see in the picture where I extended above the original pattern. 

I originally cut out a toile to test the theory of how to make the point.  Folding the sleeve in half to find the middle and then folded down in my best origami fashion.

I repeated the folding over and created a nice neat point

Then pinned the whole thing onto the robe to see if the theory worked!  I was surprised to see it did, but it needed some interfacing to make it stiff enough to hold up.

Moving onto the actual fabric I repeated the process but added in a triangle of interfacing under my origami shoulder.

All pinned securely into place it was time to hit the ironing board.

And press so there are really pointy points!

I hand sewed the seam to try and get it as invisible as possible.

Then realised the sleeve was to floppy to the outside and had to put interfacing on that too, luckily I am using the iron on stuff so I was able to add it without too much difficulty.

It has made a really sharp point that gives the effect I was looking for!

So here is where I am at, two rather nicely pointed sleeve heads!

I now need to add the lower sleeve, buttons and hem it all together and then I have one costume finished.