I don't think a lot of practice is required to become an adequate player. I believe a focused method is better than spending unfocused hours noodling around. A good instructor will help you set goals and provide a focused plan of attack. Make sure the instructor knows you longterm goals so they can help you fill in the details. If you want to learn how to play jazz, find someone who will guide you directly to that goal instead of someone who teach you how to play Chopin and Bach.

Speaking of the Vulcan greeting, I learned this finger exercise watching a Memphis-based Sunday morning magic show when I was a kid.
Hold up both index fingers
Bend them toward each other
Then wiggle both to the right, then to the left and back to center
Then straighten them up again
It's surprisingly easy to do, since you're giving the same command to both hands.
Another one he did resembled the Vulcan greeting.
Hold up both hands in a V - pinkie and ring finger to one side, index and middle finger to the other
Then switch, so the middle and ring finger are touching, and the other two are spread apart. It's a little harder, but still possible.

As both a musician rediscovering my musical past and the parent of 2 younger musicians, I have to agree with Woody:

"A place to practice without interference from neighbors, family members, etc."

is paramount. It makes me appreciate what I must have put my Mom through, and I am sure my wife is having second thoughts about getting my sax overhauled for me last year.

You need to practice mostly what you can't play in order to improve -- but folks only want to hear what you can already play well and certainly not practising altisimo exercises on Sax!! -- guess I'll have to get one of those "Sax Bags" to silence the beast!

Oh well -- next house will have to have a sound proof music room (and I'll justify it as a "home theatre room").

Any instrument you can practice (at least mostly) with headphones could be a good choice for a lot of folks.

Jim