I got this from John Kessel- Some good stuff.

My kids McKenzie and Cody got a big kick out of a recent ad in
Lacrosse magazine that said something to the effect of "The thud on
the garage door just got louder..."  Wall or garage door, this
article is a solid read all your players should be doing right now. I
know the 7th grade guys are out on the Cheyenne Mtn Junior High
concrete wall already...a good thing --- now go get your kids to dent
that garage too, or head on down with your kid and make some louder
thuds on the wall there.  -- John Kessel

Wall Ball by Paul Carcaterra
Paul Carcaterra is widely regarded as one of the top youth lacrosse
teachers in the USA. he is a former captain and All-American at
Syracuse. He plays for the MLL New Jersey Pride.

As this wonderful sport evolves, both from an equipment and training
standpoint, we are all exposed to new ideas about how to become
better coaches and players. I have been involved with the sport of
lacrosse for 21 years, at the youth/high school (Yorktown), college
(Syracuse), international (Team England), and professional levels(NJ
Pride). There were many innovative ideas that helped me become a
strong player, and now a high school (Fox Lane) coach in Westchester
County, NY. However, the single most effective training technique
that was implemented in my game, and the one that I preach first and
foremost to my players as a coach, is one of the oldest. "WALL BALL"
is the one aspect of training that can help a player develop and be
the sure handed ball control player, regardless of position, that
every team needs.

I look back to my childhood, and remember buying into this system
that was preached to me from people with names such Gait, Maracheck,
Zulberti, and Nelson. Committing yourself to 20 minutes a day, yes
only 20 minutes will improve your stick handling, hand eye
coordination, passing, catching, shooting, fakes, and trickery. The
beauty of "wall ball" is that you do not have to rely on anyone else
to get better. Just you and the wall. There are five phases of "wall
ball" below that I feel can benefit everyone reagardless of position.
Find a wall in your area (it could be the side of a school, gym,
handball court, etc) that is at least 15 yards long and ten feet high.

Phase 1-Quick Stick/Rapid Fire: Line up around 3-5 yards from the
wall. First, 50 right hand throw and catches without cradling. After
completing 50 right hand throw and catches, do the same with your
left. Did you notice I didn't mention starting with your strong hand.
With "wall ball" anything you do right, you follow-up left. This
stage is great because it allows you to work on quick sticks, hand
eye coordination, and one timing. You will become better about
getting rid of the ball in a timely fashion without even noticing it
by practicing this stage.

Phase 2-12 Yard Passing: Line up 12 yards from the wall. Start with
30 right hand throws, which will come back to you on one bounce. When
you retrieve the ball from the one bounce, cradle once, then
follow-up with the next throw. When you have completed 30 right
handed throws, follow-up with 30 left.

Phase 3-Throwing & Catching On The Run: This may be my favorite and
most helpful stage. First I start line up 5-7 yards from the wall on
the far left side of the wall. I begin this stage with the stick in
my right hand and while I am running alongside the wall (towards the
other end), I throw and catch the ball on the run. The important part
is to throw the ball on the run and not always catching the ball
stick side. I like to do this during every stage. Do you always get a
pass stick side? No. Therefore, in your training you should throw the
ball against the wall and catch it cross hand (or across your face).
After I run one length of the wall, I run back to the other end
throwing lefty (doing the same thing I did with my right). Keep
repeating these steps. This stage should be done for about 5-7 minutes.

Phase 4-Shooting: Line-up around 12-15 yards from the wall. Get in
proper shooting formation (hands loose, three quarter/overhand
motion, snapping of the hips, and following threw) mark a few places
on the wall with tape to aim at. Shoot at about 80% velocity, having
the ball come back to you with one bounce. Depending on where you
aim, the ball may take bounces that aren't the same, so you have to
work a little bit. Start with 25 right, and follow up with about 25 left.

Phase 5-Trickery: This stage is fun. This is a great time to practice
behind the backs (make sure you are not following threw too much.
Step in the direction you are aiming, and the behind the back motion
is only about a foot, with the head of your stick ending up hitting
the top part of your arm near your shoulder). Around the world, threw
the legs, and any other creative stuff can be incorporated at this
time. I would leave around 5 minutes for this stage. I am a firm
believer that this stage is important. If you can pull this stage off
(and only if you are mastering the other 4 stages should you try this
stage), it is an indication that you have a strong comfort level with
your stick and great hand eye coordination. It is also a stage that
can help you in terms pulling something off in a game that is nice to
watch and necessary. There are times in a game when a behind the back
is the only option.

So there it is, five stages of 'Wall Ball." Get a radio with your
favorite beats, a snow cap and duck boots if there is snow on the
ground, and do what you have to do to get out at least five days a
week for 20 minutes/per day. Don't let the competition pass you by. No excuses!