Morning sunlight - sets your circadian rhythm improving your ability to fall asleep quickly and maintain quality sleep through the night. Sleep is critical for test.
Diet - cut out packaged, processed foods. eat fruit when you want something sweet, your basic staples should be eggs, ground beef, chicken, greek yogurt (that covers 80% of my daily caloric intake)
Sprints - there are solid studies on sprints increasing test levels in men drastically more than other forms of exercise
Lifting heavy - following sprints, lifting heavy weights is a necessity for high test level
Competition - engage in sports/events which force you to compete with other humans, comfort kills testosterone