Kylo Ren build, extreme beginner!

I finally got started on my Kylo Ren build after what feels like months of research. Truth is, I'm a full time undergrad and I work full time, so now that summer is out I can finally get going on this!
Sadly, my first post is one with problems and questions.
I chose a fantastic material for my sleeves, however I tried to cut corners. I should note that I have really never sewed in my life. I bought a sewing machine, played around with it some, and now I'm off and running, hitting every hurdle so far.
I chose this fabric:

It has a rubbery texture that is elastic also to complete the form-fitting feel the sleeves have. I then began to pleat them by just pinning and pressing. I like the fact that the costume has imperfect pleats. Some are smaller than others, it's not uniform. It's not that I was trying specifically to achieve this, merely a result of my lack of ability in all things cloth!

While it looked perfect, the minute I sewed it, it unraveled, predictably. I had a pretty good fit for the sleeve, but when I tried to put my arm through it just fell like spaghetti, my pleats lost, or at least temporarily however, due to them being sewn at the seam of the sleeve.

So not to be completely dissuaded by this I began trying to salvage what I had left. I bought some of the double sided iron-on adhesive and began placing it under each pleat. I used a poster tube to keep the shape of the sleeve while ironing these on. I eventually came out with something that looked a little more correct, however the glue does not seem to hold very well as I can't get the iron quite hot enough to melt it without damaging the fabric also.

And so at this point I'm about ready to start over before I invest too much time into this somewhat futile effort, however having never actually sewed pleats before (as I'm sure it's supposed to be done) I'm in search of a little help. So I turn this over to the community. What is the most effective way to get the pleats to come out correct, and also are there any tips on sewing the sleeves themselves? I am as new as it gets to sewing in general so don't be afraid of pointing out the obvious, to me it might be the thing I'm missing.

Update:
I began experimenting with the sleeve pictured here. I took apart the seam and decided to try to sew the pleats down. Wow... I should have started this way. I overestimated how difficult it would be, and how scary the sewing machine is. Things are moving much smoother now. Hopefully I'll be making progress soon.

Re: Kylo Ren build, extreme beginner! (In dire need of pleating help!)

Yep! The flat base and sewing them down is the way to go.

Re: Kylo Ren build, extreme beginner! (In dire need of pleating help!)

Just a small update: After deciding that the piece I was working on was going to be "experimental" I figured I may as well try to get the right fit out of it. I've seen people use patterns but I'm not entirely sure how they work, so I'm modeling these items on myself and trimming them accordingly to get the desired fit.

I found this to be a solid technique to get the exact right fit I wanted with my sleeves, where I pinned the zipper on the edges and continued to move them in/ out depending whether I needed more or less room, then I eventually sewed them down to get a good feel for the fit once I had gotten it as close as possible. It was certainly a good idea to have this piece as a practice prototype of sorts as I've never done any of this before, and so now going into my actual sleeves I think I have a better idea of what to do and how to do it.

So ignoring the bad pleating which I've now learned to correct, and the absolute lack of pleating toward the top where it fell apart, this is somewhat of the prototype for now, something I can use as a reference for Mk.2 which will (hopefully) be the actual sleeves used in my costume.
I've learned a lot in the couple of days I've been playing with this! Time to put it to work.

Re: Kylo Ren build, extreme beginner! (In dire need of pleating help!)

So a few months have passed by, and I'm finally learning to use my sewing machine.
I have finished both sleeves and attached them to a base shirt, a little neatening up needs to be done but that's coming along. I am now working on the pleated tunic, having gotten the body of it complete I am now fitting it and sewing it. I just piped the first sleeve hole, and I have to say... if i thought sewing pleats was annoying then sewing piping onto pleated material just took the top spot. Anyway things are moving along, I test fitted the sleeve hole as you can see in the pictures and it seems to fit pretty well, not perfect but again, at the beginning of this project I had to watch a youtube video on how to thread my sewing machine, so being as novice as I am I'm not expecting miracles!
I will post a better update soon as I'm finally making progress.
Lurking in threads on here has been very helpful! Thanks to you all.



If anyone has a fix on how to make these images not upload sideways, that's be great!