If you're an occasional DIY plumber like me, use dope. (I used Oatey Pro Dope from Home Depot but I'm sure it's nothing special.) Cover the threads completely on the male fitting. Tighten with opposing wrenches until it feels like you'll break it pushing harder. If you don't have that feel, use maybe 6" long wrenches for a 1/4" fitting, 12" wrenches on a 1/2", and big pipe wrenches on bigger - then tighten until you can't really put more force into it. Of course if orientation is key, try to get at least one full wrench turn and then more to orient.
I built an all lead-free brass well tank tee with four different NPT sizes, and I found that I needed pipe wrenches for the 1/2" and bigger. A pipe wrench is made to dig in and grip tighter with more force. Open-end or adjustable wrenches just slip. Luckily I inherited 3 pipe wrenches from a grandfather so I had what I needed.
I got 100% leak tight mating with dope and no additional tightening after pressurizing. That was my second try. First try I used thin teflon tape and got 100% LEAKING even tightening more than I felt comfortable. The dope was easy and did the job.