Folding a tortilla so that its guts do not fall out is second nature to me as I have been doing it forever and I don't have to think about how to do it. When writing the chimichanga post this morning, I was going to post a link on how to fold them except there is very little information out there. I decided that I would instead fold one and take pictures of it then realized I had no tortillas and nothing that I could fill the tortilla with to demonstrate. I then decided that I would make a single tortilla and use a piece of ginger root as "the guts " so that I could post this...
Note that home made tortillas are not going to be perfectly round unless you are just that anal about things. I personally like the weird shapes that my carelessness in rolling provides. It makes rolling them up more challenging.
start with a large slightly warm tortilla. The bigger the better and lay it on a flat surface. Place your filling on the tortilla, leaving a couple inches on either end and enough room on the first flap to be able to cover the filling. Do not over fill the tortilla. If it starts oozing out the ends as you fold them in, its too full.
Fold the first side over the filling and fold in one end first and then the other end.
Once both ends are folded in, continue rolling the tortilla until there is just a small flap remaining. Make a little paste from flour and water and glue the seam together.
When baking or shallow frying always put the seam side down or it will open up in the cooking process.