Another Dremel-fu technique
Don't use a Dremel ;) For many Dremel-fu operations, I use a Dremel bit is a drill press. Cutting off the threads on a sink tube is easy if you adjust the platform so that the cut line matches the cut-off wheel height in the drill press. Just slowly turn the tube on the platform and you get an ultra-square cut on the tube. I also grind grooves for o-rings in a similar fashion (tube horizontal rather than vertical). Sanding and grinding, as well as brushed aluminum techniques work equally well using Dremel bits in the drill press. I find the mass of the drill press helps to reduce kickbacks and slips.
Unfortunately, things like the curved top of a Graflex template still require free-handing a Dremel tool.