Sweat or threaded connections for shut-off valves
I've had better luck sweating/soldering Cu connections than the threaded-with-tape approach.  Another option is to use SharkBite (tm) or equivalent push-on connectors.
FYI, I just added a hose bib out the front of the crawlspace.  8 fittings total with 6 soldered, 1 Sharkbite, and one threaded.  The only one I had a leak issue with is the threaded joint.
Edit 1 - Nap should be Mapp
If you're going to go the solder route, I highly recommend a Mapp torch rather than a propane one.  The Mapp heats up the copper a lot faster than the propane.