I'm not sure how much I have to offer when it comes to cutting out the fabric pieces for your garment. It's pretty much the same in any language, and different people have their different ways of doing it. I'll share what I do in case it's helpful.
Tip #1 How much fabric to buy? To be honest, I really haven't put much effort into trying to understand the Japanese pattern books instructions for how much fabric you need. There are some measurements printed on the cutting diagrams. The one I'm working on now says 150 cm wide and 50 cm tall, but it's doubled. I assume then that when folded, it should be 75 cm wide, but I don't really know. What I do know is about how much fabric it takes to make a short sleeved shirt for 4-year-old Addie (about a yard), a pair of pants for Addie (about 1 1/2 yards), a short, straight skirt for Addie (about half a yard). So my tip here, which really isn't much of a tip, is get the fabric amounts from other patterns you have (or take a peak at the ones at a local fabric store) that are similar. Or you can just go with your gut feel.
I don't try to cut the same way they show in the pattern diagrams. That just seems to complicated to me. If I'm worried I won't have enough fabric, I kind of lay out the body pieces and sleeves, and if it looks like I'll have enough for those, I go for it. I figure there will be enough scraps for collars and facings - or I can always use a contrast fabric for those.
Tip #2 Look at the cutting diagram to figure out what fabric to cut. The diagram below is for the blazer I finished over the weekend and posted about yesterday.
You can see that there are two different boxes. The one on the bottom is showing me to cut those pieces in contrasting fabric. Then the dotted pieces are telling me to cut interfacing - in addition to the piece out of that fabric. (At least that's what I think. I remember thinking how cool - how revolutionary even - it was that Japanese patterns never called for interfacing. Then I realized that I wouldn't really know whether they did or not and started noticing the dotted pattern pieces. duuh.)
Oh yeah, and that really elongated "C" between the two boxes is telling you to fold the fabric above. The fabric below is not folded. You can also see in the upper right corner of the top box where a corner of the fabric is folded down the reveal the two layers. It's really all in the diagrams - and pretty straightforward once you get used to it.
Tip #3 How I cut. This really shouldn't be a tip at all. This is just how I do it. In blog-land, I've seen several people using pattern weights and rotary cutters to do all their cutting. I'm very intrigued by this but haven't been brave enough to try it yet. I stick with the old method of pinning down all my pattern pieces. Here's a shirt back piece all dutifully pinned to the fabric.
You can see that I don't bother to precut all the pattern pieces from the tracing material. I just cut it right along with the fabric. Then the pieces are all set for the next time I make the same pattern without the extra step.
Tip #4 Mark your fabric. I like to wait until the last minute to do this - until I'm actually going to use the piece. It helps remind me of sleeve placement, button placement, etc. closer to the time when I'm actually going to do that. So unless I'm running out of pins or need to reuse a pattern piece, I leave it pinned to the fabric until I'm ready to use it. Then I snip all the little snips (you know the little tick marks with the circles on the end that I mentioned in Tip #9 here) and mark all the other things - buttonholes, pocket placement, etc. either with pins or my fabric marker. The other advantage of waiting to do this until the last minute is that pins can fall out and fabric marker can fade.
That's it for cutting tips. I'll be back soon with sewing tips.
Thanks for reading along. I hope you're getting inspired and not overwhelmed.