Here are a couple of things to consider when going through a long toss program:
1. How does my arm feel today? The more I throw, the better my arm feels, but there will be times when a day of is needed. Learn your arm!
2.Intent-If I am going to gain arm strength, I must throw the ball with greater effort than I do right now. My intention will be to throw the ball as hard as I can, as great of a distance as I can, for as long as I can. Any other way, long toss becomes more of an endurance, get your arm in shape event.
3. Compress your throws. After throwing the ball as hard and as far as I can, I want to "compress" my throws i.e.-taking a 300 foot throw and turning it into a 60 foot 6 inch throw. My body organizes itself to do a certain task-a 300 foot throw will be different than a 60 foot throw. My job is to compress/organize to maximize my delivery.
4. Injury occurs from many things-overuse is a major one....if I practice putting greater stress on my arm in practice, then won't the stress of the game become less? If I throw sub-maximally until the game starts, won't the stress be greater in the game-my arm won't know how to handle this.
5. If you had one rule to follow, it would be this: throw hard and throw often!
My 2 cents.