You generally don't stir cake batter at all.
Where I learned to bake, we were taught that if you want a light and fluffy cake, as is generally the case, then you should fold in the dry ingredients (including flour). That means using a flat surface - a silicone spatula works great but you could even use your hand in a pinch - sliding it down the edge of the bowl, and using a turning motion (i.e. folding) to incorporate the flour, repeating several times until there are no longer any large clumps of dry ingredients.
When you fold, it's very difficult to over-mix. And particularly with cakes and quick breads, under-mixing a little is actually OK, because the batter tends to be quite moist and eventually the moisture will seep through to any unincorporated flour - and if it doesn't, you'll get a nice spongy texture.
Commercial mixers actually have paddle attachments for folding large amounts of batter. You don't need a special mixer, though; you just need to be gentle and conservative with your mixing.
Not every cake is the same, and some recipes may specifically call for you to whisk the batter (for which you should use a balloon whisk, not a spoon or spatula) instead of folding, but if it just says to "mix" the batter then I would using the folding technique.
The Good Eats episode on pies suggested this too. Alton Brown refrigerated the dough before forming, formed it, then re-refrigerated it.
He explained that taking it out of the fridge to form the base would be enough time for some of the butter in the dough to soften and potentially melt. This would undo all the work put in previously to keep the butter intact within the dough.
Best Answer
Well... Pie dough? Flour, fat, salt and water. I recommend lard for flavor and texture.
Alternately, a graham cracker crust can be had by putting the crackers into a plastic bag and rolling with a heavy rolling pin until fine crumbs. Then mix in butter, press into a pan, and bake until fragrant.