I'm working away at getting the perfect process for making my white cathedral window bases. Test squares like this one will probably end up as a pincushion, I'm using my favorite fabric bits.
My starting how-to point has been this fabulous tutorial. Bookmarked at least a year ago, as I'm sure SO many have, the only think I've eliminated all together is her batting step - and the hand sewing of course.
I prefer my points to meet square and non-lumpy. Much work is going into that end. I'll be sure to share my optimized process once I reach it. Tacking down those center tips, before turning the edges, seems to help.
The physical making of those fabric origami squares isn't my favorite thing. I timed it - a sure sign of my hate for it - at 8 minutes per square. Included in that 8 minutes is quite a bit of steam-burning myself. So I've changed the corners at the first step and added the Sewline glue pen to my process, things are going better. It's like an extra set of fingers, that don't hurt if they get steam blasted.