If you are at the stage of finally finishing your basement, you probably have two insulation concerns: how to keep the basement warm enough that people want to be there in winter, and what kind of insulation is best. If you make the right choices, you can create a draft and fire stop in your basement and save yourself some framing headaches.
Insulation concerns have to do with the kind of insulation you use and how much to use and how best to use it. Blown-in insulation is a great option for basements because it fills itself around wiring and into tiny crevices that you don’t often notice when you are stuffing an insulation batt into a wall. Those cavities between studs fill nicely with a blown-in system, which, in turn, creates that fire and draft protection you want. If no air can blow freely through a spot in your wall, you not only prevent drafts from entering in the basement, but you also prevent drafts from feeding a fire in your home, should that ever happen.
Using that same blown-in system to insulate the ceiling/floor area between your basement and the main floor creates those same barriers, and again, a blown-in system is more effective at filling in gaps and preventing drafts.
The amount of insulation you need depends on what you are trying to achieve. An R11 is the minimum you need to pass inspection, but you can stuff more in and achieve higher densities for draft protection as well as for muffling footsteps and keeping the noise levels down. Most people don’t’ go above an R20, which is a good level to hit.