I can honestly say that being on the varsity roster even for one down, game etc.. gets you a varsity letter is the only way I've ever heard of. Not saying it is the only way just that I haven't heard of any other.
Mind Gym: An Athlete's Guide to Inner Excellence
by Gary Mack,
The Champion's Mind: How Great Athletes Think, Train, and Thrive Paperback – May 12, 2015
by Jim Afremow PhD
Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Success
by Brad Stulberg
Sorry for the lateness of my reply but long tee would be hitting off a tee in to an open field instead of a net. It provides better feed back for the hitter.