Anything could be as big or wide as you have room for, so dimensions are kinda Meh'. That just leaves making the lines. This is why I much prefer pencil and paper to some computer based drawing thing. Look at the pics, and try to sketch it so you get a similar form. Next thing ya know, you've drawn a template to roll your own.
I load these onto a thumb drive, and go to the Kinko's or similar place nearby. So far every time I have done this, either anyone working at those places can do it, or I've run into good luck, because I can then have them make me copies to use to make 6' tall, down to 6" tall, and back to the shop I go with plans in hand, or I should say templates. I spray adhere them to a piece of plywood, or hardboard if I think I'm going to make several. If I am just making one, I'll just spray adhere the paper right onto the wood, and BS it out. If it's a drawing where I know I will need to cut essentially the same cut, but at different angles or overlapped, I'll just have them copy me a few prints.
Can't remember using anything except online pictures to make my own plans, especially for something like this, where even a little off, still works just fine.
So a video to show the cut sequence if you're not sure, and paper drawings to show you where the lines are, are essentially a plan. If you sketch it, those differences will be enough so that yours isn't a cookie cutter representation of everyone else's, so it's unique look will make yours a one of. Winner winner chicken dinner.. :-) Biggest plus is if you have never done it, and just go step by step, you will end up learning how to do this for even more complex, and detail laden plans. Pretty soon you will have more $$$$$$ in yer pocket from not buying plans, and be able to buy more tools, wood, or just take the ones you love out for a nice dinner. Yet another WIN. :-))