The Kawasaki rose was the first one that I came across, and initially had some difficulty with it, but managed to figure it out eventually, though I never was quite pleased with the result. The rose just somehow looked like an odd approximation to my eyes, so soon enough I was back to trying to find a 'better' one.
In my search I came across one of the most amazing roses that I've seen, created by Robert J. Lang (gosu x2) and immediately wanted to learn how to create one, but, as professional origami artists go, all I had to go on was the crease pattern.
The first thing you'll notice about the pattern is A. how amazingly simple this pattern is, and B. how specific the measurements are, and how there are an odd number of sections on the x-axis. This proved to be a difficult matter for me (a non-math person) to deconstruct, but with help of the internet I eventually found out that the pattern should through a series of folds collapse into a pentagon (see below). I however didn't want to have to take the time to divide the whole piece of paper into 80 parts, and then reassemble them into the proper proportions, so I have been for a few years now, cheating with a general close approximation of the sections. In doing this I measured the square which was approx. 248x248mm (9 3/4"). I then took that number and divided by 11 and 80, and then rounded the multiples so that each section was at least somewhat close. So on the y-axis, I eventually used 18.5, 22, 25, 28 and 31mm which aren't exact, but close enough. The x-axis was approx 22.5mm for each 11th. It ended up that the 5th and largest section was a little larger than the others and the final 11th was about 2-3mm too large, but as I've worked with a few times, it still works, just not perfectly like Roberts measurements do. Oh, I should probably quickly mention that if you do the quick and dirty way like I have here, if you aren't close to the correct measurements that collapsing into the base will either be inordinately difficult, or impossible depending on how off the creases are.
bottom view
and how each section is larger slightly than the previous one
Once all of the creasing of the pattern have been done comes the hardest part in my opinion, collapsing it into its pentagon. Without the help of This blog, I'm not sure I would have ever figured out how to collapse it properly as I am a very visual person, and staring at a bunch of mountain and valley folds has always been a tad confusing. In fact, that blog gives a very good explanation of and links to the discussion of figuring out how he originally did this.
Anyway, I wanted to share the pictures of the various steps in making this so that if you wish, you could attempt this as well. The first time I ever attempted this, I printed the crease pattern and tried it from there as a reference.
accordion the paper and make your fist set of folds at the end
From here you have to do a series of the same folds, so that the base rotates during each fold and that you have to open up your accordion in order to make these folds each time in succession . Below is the first set of folds:
this step is repeated 4 times for each of the 5 sections
Once this step is complete, repeat the whole process 4 more times until you have your pentagon
Now the fun part, shaping it. I generally have been twisting the base as much as I can so that I can not only fold part of the bottom base in on itself (holding it together), but also so that I can get a nice spiraling effect with the petals. Below is the tightest that I am able to twist without ripping the paper.
I should also note at this point I'm pretty sure I'm diverging quite a bit from how Robert Lang would shape his rose, as I am only guessing as to how he does that.
Once I've held this a bit, I then fold the bottom base in on itself and begin to curl and shape the petals with a pair of tweezers because hell, my hands are way too big to be able to make these kind of minute adjustments properly and get a nice look to them. Below are a few images of the final product after all of the shaping involved, hope you enjoy them: