Take a look at this submission from Bert.   Two great suggestions for [tag]baseball strength training[/tag] that can be done at home and that can work with all age groups.Baseball Strength Training

From Bert…
Simple and fun strength and coordination exercises to do at home. These two simple exercises, which can be performed at home, help address two of the areas Ted Williams preached were the most important when it comes to making consistent contact: wrist strength (for bat speed) and hand eye coordination. (Williams also preached hip rotation, but that was for power.)

Wrist strength exercise – Have the [tag]baseball[/tag] player grip his favorite bat at the butt end, as he or she normally would when holding the bat. Start the exercise with the bat in the right hand, the arm fully extended, parallel to the ground and in front of the ballplayer, and holding the bat in the vertical position.   Keeping your shoulder and elbow still, slowly rotate the wrist to the right until the bat is horizontal (parallel to the ground) – do not allow the bat to go past horizontal. Now slowly rotate the wrist to the left until the bat is once again parallel to the ground on the other side (the bat movement will resemble that of a mechanical metronome). Start out with 3 sets of 3 (in each direction) with both the right and left hand. Work up to 3 sets of 10 with each hand. Also, increase the bat speed as the ballplayer’s strength allows.

Helpful Hints:
Before starting the exercise, take a few moments to –
Warm up wrists by simply shaking them gently and loosely for about 10-15 seconds. Warm up and stretch the shoulders and elbows. If the ballplayer finds the bat is too heavy to perform the exercise properly, choke up a bit.
After the strength exercise sets are completed, stretch the wrists by doing one more set, but this time, as the ballplayer brings the bat from the vertical position to the horizontal position, allow the bat to slowly pass below the horizontal position thereby gently stretching the wrist. Perform 1 set of 5 reps for both the right and left hand.

Hand-eye coordination exercise – Holding the bat with one hand (the power hand (right for righties, left for lefties) somewhere just below the middle of the barrel, bounce a ball on the sweet spot of the barrel (this [tag]baseball drill[/tag] will also teach the ball player where the sweet spot is). Try to do this ten times without missing. Do three sets of ten (it will take several tries). It may be hard at first, but with practice the ballplayer will be able to do it relatively easily. This also helps discipline the ballplayer to try to watch the ball hit the bat.

Helpful hints:
It may be easier to start out holding the baseball bat with both hands, but eventually work back to one.   It is fun to have a contest at [tag]baseball practice[/tag] to see who can bounce the ball the most times without missing.   Do this drill outside or indoors where you can’t break anything (the balls tend to fly around, especially at first)
You will see the results at batting practice and at the plate – quicker bat speed and more consistent contact.