Based on advice in a prior thread, I swapped out my bad undersink
shutoff valves, and replaced them. For the replacement, I installed
compression fittings and an adapter for valves to thread into. I am
getting dripping where the valve threads into the adapter.

It doesn't seem like I should have to keep tightening as much as I am.
I hurt my right thumb recently, so I don't have the strength I could
right now, but I still have it very secure. Is there something I need
to help seal? I'm wondering if rubber washers or some kind of putty
needs to be applied.

If it's just elbow grease, then I probably need a better (longer)
adjustable wrench so I can torque these things up.

My other problem is the existing connections to everything assume the
valves are oriented a certain way. If I keep turning the valves, I can
no longer make these connections. I have a hard time believing
tightening is my only option.