I discovered something recently for practicing at home.
I have Joe Tucker's Third Eye stroke trainer. He suggested using
a glass in place of a ball if you don't have a table, but I found
something better. I like to juggle, and I have something called
Klutz Juggling Balls. You can buy these at any Barnes and Noble
for about $8. They should be in the kids section in a big Klutz
standee (just ask). They are square, but are exactly 2.25 inches
across.
So, you set these on a table, and stroke into them with the stroke
trainer. It's nice, because it gives you something to hit, instead of
just air. And since they're square, they don't roll off the table.
Then you can take the stroke trainer off, and stroke some more.
I recommend cleaning the chalk off your tip first though.
If you can create some sort of a long straight line on the table,
you can ensure that everything is really really nice and straight
in your stroke. Line up straight to begin with, and compare your
stick to the line at various positions: Full backswing, cue ball, and
full finish/follow through.
For even more fun, if your phone has a video camera on it, you can
record yourself from different angles, and see what you look like.
I recommend talking about what you are doing, because you may
not remember when you go back and watch it. If you have a
computer, you can save these videos and watch them later for
comparison of your progress.
I've learned a lot from doing this lately. You can really focus on your
stance and bridging this way. There is no ball to
pocket, so you just focus on those things. I've also been doing
it left handed, and it has really helped my left handed game. I can
now make balls consistently, though not really play position yet.
I also am starting to develop that feeling of power, like I have with
my right hand. Where I'm not just hitting the cue ball towards the
object ball, but stroking it.
And of course, once you finish stroking, you can use the Klutz Book
to learn how to juggle. Tips on that: Learn one ball, then two. Then
go back to one ball again. Then two and three. Then one ball again.
It's about good throws, not good catches.

I used to play music
instead of counting my catches once I got good enough. I would
try to juggle for an entire song.