Practice Plans:
Practice plans are the second most important thing in developing talent for your team (behind recruiting of course and, in my opinion, followed by getting your young guys a little playing time). Each player has 130 minutes of practice time. Each player has an Individual Practice Time of 130 – Team practice Minutes.
Team Practice:
For team practice you decide how much you want to improve your players IQ's. Most coaches will use 20 minutes in each Offense and Defense, you can be very successful by always having 20 in each and never changing it. It is highly recommended to only have one of each (although combo D’s are available at the lower levels players have to much individual improvement that its advised to only run one). Although it is your team so if you want to try having 2 different O’s go for it (Still I would not recommend it).
Some coaches change Team practice minutes based on how young/old their team is. With very large (possibly super-class size) freshmen and sophomore classes I advice to bump up the O/D at least a couple points. I usually run my D (I play mostly press where IQ is more important to cut back on excessive fouling) practice at 25 minutes and my O practice at 20. If you have a very big Junior/Senior class you could even possibly choose to cut out team practice altogether. IQ levels do not go down even if they are not being practiced. Players also improve their IQ by playing in games.
In my experience The point of diminishing returns is around 25 practice minutes in a single category. So anything over 25 will give you less then 1 minutes practice. It is ok to put more then 25 into a category, and is sometimes even the best thing to do. However, most times I rarely go above 20 unless the player has way too little to improve (especially early on in their career).
This is usually what I use when setting players SH minutes at the start of a season:
Freshmen: 7-10 depending on HS GPA
Sophomore: 5-7 depending on Cum. GPA
Junior: 0-3 depending on Cum. GPA
Senior: 0-1 depending on Cum. GPA.
Note: Treat a Red-shirted Freshmen as a regular Fr.
Note: There are 2 mid-terms and 2 final-grades. This gives you an opportunity to change your SH minutes if your players are in trouble of failing. Once you get your 2nd set of Final Grades. You can take all SH minutes away from players and put them into other categories.
Note: If a player becomes ineligible during the season he will still practice with your team, he is just not allowed to play. So Do NOT move all his minutes over to Study Hall, just enough to get him eligible (Which could be anywhere from 10 to anything depending on his year and his gpa).
Off season Improvements:
These are random, based off a players Work Ethic, Practice Plan doesn't matter. Meaning a player with a higher WE has a better chance of gaining more in the off season. A player that has a lower WE has a lesser chance. Usually a player with under 30 WE losses points in SPD/STA/DUR in the off season.