Tryouts

My suggestions would be:

Make sure players rotate through a number of sets - e.g. 2 or 3 balls 5 times rather than 15 balls in a row. Too often kids will muff one and then start pressing - breaking it into sets gives them a chance to settle down after a mistake... and seldom do you see an outfielder get more than three fly balls in a row anyway

In the scrimmage, make sure that it is a continous batting order and than the order is followed - I have seen multiple tryouts where kids will get squeezed out by more aggressive/bigger players.

I also like to break the tryout into groups and rotate them through stations - keeps every one busy.

Depends on what age group and what type of team.

Coach,
It is terrific you have had such a great response and will have lots of players to choose from to fill the "few spots" you have available.
I would think you have an idea what spots you need to fill (ie. 2 pitchers, a middle infielder, a catcher, etc...). If this is the case, you should focus on the skills needed to play these positions.
Are you having the whole team tryout, even the kids who are already locked into a spot? If not, you can definitely focus the tryout how I described above.

Just a suggestion its your team. Have a tryout. Have all the kids tryout even the ones already on the team. You may be surprised. Also you will let your guys know that nothing is a given. You will have to earn your spot every year. Also you will be able to gauge talent better by having kids out there side by side with the players you are evaluating. Good Luck

line them all up at shortstop. Hit them a few ground balls have them throw to first. It will tell you a lot.