I agree with what many have written. As you play, when you encounter a pivotal hand (lost a lot, won a lot, or you really questioned your decisions/actions), make good notes about the hand. Be sure to note what stage of the tournament, blind levels, chip stacks, positions at the table of active players, action on each street, and later add your thought processes. Then, take those hands and analyze them yourself and with trusted poker friends on this site or off. Look for similarities, like overplaying top pair or overdefending your BB, etc. You will see some trends of being in a certain position, situation, type of hand, or reaction to a certain type of opponent. It will take a lot of time and dedication. Good luck!