Well, you can achieve maximum possible testosterone levels by doing a few things.
1) Squats and Deadlifts. These will release a great deal of GH and IGF-1 (I believe) which will significantly boost test levels. If that's not the exact science behind it, at least trust me when I say that these two movements will in fact raise testosterone levels.
2) Sleeping 8 hours a night, minimum. This will ensure you get the best possible progress from your training, as once you enter Stage 4/R.E.M. sleep after I believe four hours of consecutive sleep, your body will release hormones necessary for growth and optimal recovery. Again, something like that. I'm no expert.
3) Have 30% of your day's calories come from fats. EFAs, especially. These healthy fats help to produce natural test, and increase levels.
So, sleep, eat healthy fats, and lift with whole body movements.
Oh, one final thing would be to stop masturbation. After seven days without jerking off, test levels boost approx. 157%. Do a search on serum test levels on Google, you'll find a study or two about it. I try to hold off as much as I can, but when me and the girl get too pent up, anything's bound to happen, so I don't hold myself down too hard to this one. If you can do it, try. If not, don't worry.