I use a similar method mentioned by Paul LeMasters. I keep all the pieces under tension with double sided tape. I build the "skeleton" of the kite first, all of the initial pieces are hot cut and once the skeleton is completed, the double sided tape does all the work, allowing me to simply place more fabric while keeping everything neatly flat and then use curved sharp scissors to cut along the lines of the double sided tape, I get beautiful clean cuts that look like they were laser cut but it requires very sharp scissors. A few pictures of my recent build bellow illustrates the beautiful results!