Althouh I use AucTeX, which already has nice quick-writing techniques, I have found emacs' abbrev-mode together with skeletons a nice addition to quick-writing in LaTeX. The included examples are for mathbb and theorem environments. I write \mbb, and then when I open the left {, it gets expanded to mathbb... so I have \mathbb{ as needed. With the other one, I write \bth, press space and get a