This is the drill we ran all through high school. It is the most time effective and skill intensive way to warm up a team, but your boys must be able to play catch! Fungo-ers stand in the "fungoe circles" that any good field has (and if it doesn't, you know where they're supposed to be - just outside of the home-plate dirt circle, towards the dugouts). The catch to this method is this - you have two first basemen, allowing both sides of the infield to throw across. Herein lies the only danger - one of the firstbasemen has a lengthy throw back to a shagger, so caution must be excersized (a catcher with a good head on his shoulders really helps).
Now to confuse things. First we start with outfield pregame, two fungoes, but the two firstbaseman thing doesn't start until infield does. So, both (or all three depending on the makeup of your team) players play "real" first.
First base fungo hits fly balls to center field (helps here if both fungo hitters move up and apart, hitting from about the front of the mound extended towards the bases). Center throws to second, second baseman is cutoff (for us it was, anyways - change to suit your style). Third base fungo hits balls to left field, who throw to third, with a second shortstop as cutoff (but you really don't need one, if you're shorthanded).
Then, first base fungo hits to right field, who throws to second, second base is cutoff. Third base fungo hits to center, who throw to third (off SS is cutoff).
Next, third base fungo hits to left, who throw to second, SS cuts (make a few of these the "cut off a double on a ball hit into the corner" variety - timing becomes important here, as the other fungo needs to hit many fewer balls than the fungo hitting to left). First base fungo hits to right, who come home, first baseman is cutoff, 60' from home (about pitchers mound - this postitioning puts him out of harms way should the SS overthrow second). On the throws home from right, make sure that they are the "normal" kind - hit the cutoff man, and don't hit too many. The right fielders will get to go again, as they're last throws will be the "do-or die" variety.
Next, the third base fungo hits to left, who come home, third baseman cuts (again, 60' from home, about the pitchers mound). First base fungo hits to right, who throw again to second (this is where we practised cutting off doubles on balls hit into the right field corner - it's really practiseing hitting your cutoff man quickly than anything else - also the reason it's safe to do while left field goes home).
Then, third base fungo backs off, and fist base fungo hits to center, who come home, first baseman cuts, right behind (second base side) the mound. After all of the center fielders have thrown the last "do-or-die" ball, the first base fungo hits one more ball each to the right fielders, who throw their "do-or-die" ball, and sprint off the field.
Make the last ball on the "come home series" a "do-or die" (i.e. give it everything you have to gun the guy at home) and sprint off the field. Wait for a while, support your infielders warming up, and be ready to form the high-five line (discussed later).
Now to the infield.
First, the third base fungo hits ground balls to the second baseman (this takes some doing to avoid hitting the mound, but it can be done), who throws to the deep first baseman, who returns the balls long and soft to the shagger. Meanwhile, the first base fungoe hits balls to the third baseman, who throws to the normal first baseman.
Secondly, the first base fungo hits balls to the third baseman, who turns a double play with the second baseman to the normal first baseman, while the third base fungo hits balls to the shortstop, who throws to a shortened deep firstbaseman (this means that the deep firstbaseman stands closer to the shortstop than normal, so that the throw across this infield is the correct distance - this does NOT mean that the deep man stands any closer to the normal first base position - this length should always be sufficient)
Third, the first base fungo hits balls to the second baseman, who turns two with the shortstop and the normal first baseman. The third base fungo hits balls to the deep first baseman, who plays in normal fielding position (again, only much deeper, towards right field).
Lastly, the third base fungo hits balls to the shortstop, who turns two with the second baseman and the normal first baseman. The third base fungo continues to hit balls at the deep first baseman, who plays in normal fielding position, only deeper. Here, change first baseman, so that both get practice recieving throws and fielding ground balls.
Then, have one fungo quit, and the last do one slow roller play throw to first to each fielder, then one slow roller play at home from each fielder. Players sprint off the field after their throw home, and line up along the first base line, giving fives down the line, and break it out with a cheer when everyone is done.
This sounds like a lot of information, but with a little practise on the coaches part, it runs quite smoothly. Two to three reps per player in the field per section is quite adequate, and with 14 men on the field, this whole routine should take about 7 minutes. It's quite snappy, and quite impressive. I had many a parent marvel to me after witnessing it - "you look like a professional team!" I wouldn't try the routine with anything less than a 14 yr old select team, but with the talent to do it right, it's fantastic.