Soooo, I have been fussing with this for a long long time and though I still feel I have lots more learning to do, I thought now would be a good time to collect my thoughts and pass them along (in hopes that others would add to this and help me make even better torts).
Things I know:
--The very worst fresh tortilla I have ever made is MUCH better than the best store-bought I've ever purchased. (This is important to remember when you're scraping off a mis-shapen blob.)
--The masa preparado I can buy in Northern California is MUCH too wet to work with when fresh.
--that cheap little cast aluminum machina is worth its weight in gold when making tortillas
--it's quirky/difficult to get the griddle/cornal heat correct
So here's what I do--please let me know what YOU do!!!
1. trim a zip top freezer bag to fit my machina (leave a tongue to slide through the hinge area so the plastic stays where it's meant to be.
2. Form the masa in balls and let air dry for ~24 hours. (The balls should not be sticky to the touch. When I dry "too long," there's a darker splotch on my tortilla but the taste does not suffer.)
(I have now figured out I should do this when I buy the masa, and then put the dried balls in the fridge--I haven't tried this yet, but I believe it will give me much more flexibility in impromptu tortilla making.)
After your griddle is hot (hard to determine the right heat on someone else's stove, sorry):
3. Place the ball a little south of center on the machina.
4. Press down. (If you like thicker tortillas, feel free to stop pressing before the machina forces you to stop.)
5. Peel the tort off the top plastic piece--holding it in your other hand and then peel it off the bottom plastic. (If your masa wasn't really dry enough, this will be very difficult and frustrating. The VERY best thing to do here is wait until tomorrow. If tomorrow's not an option, it's easier to pull the plastic off a too wet tortilla than it is to peel a too wet tort off the plastic.)
6. lay the tort onto the griddle
Repeat steps until you have no more griddle space.
7. Flip torts
If they puff up you can be pretty sure they're ready to take off the griddle, but loooook... do they have that nice speckle look? You may have to taste here. (I did until I got it down.)
8. Place torts in a stack inside a nice clean folded dish towel. (This step helps them get more bendy--mine are pretty stiff when they come off the griddle.)
And please share what works for you!!!