1. Raise your expectations of everyone and everything. If you learn to expect the best possible outcome, you're bound to be met by disappointment. So put all of your eggs in one basket. Rely 100% on friends, family, and business associates to do as they promise. And If you crank your expectations to eleven, I promise you a deep sense of injustice.
"What makes us angry are dangerously optimistic notions about what the world and other people are like (…) our greatest furies spring from events which violate our sense of the ground rules of existence" - Seneca
2. Never gain a new perspective. Don't step back and see things in a different light. Never consider how small you are in the greater context of our universe. Lock yourself behind your eyes, and see a world that revolves around you. The longer you're able to maintain this illusion, the more primed you'll be for despair. You'll know you're headed down this path when random events feel like cosmic forces, aimed only at you.
“One of the symptoms of an approaching nervous breakdown is the belief that one’s work is terribly important.” - Bertrand Russell
3. Believe that you can control outside forces, circumstances, and events. Then feel betrayed when life doesn't go your way. Take it personally, and spend a lot of mental energy thinking about how it makes you feel. I know of nothing quicker to bring reliable unhappiness, as a false feeling of control over outside events.
"…if you desire any of the things which are not in your own control, you must necessarily be disappointed…" - Epictetus