Gambling should always be treated with a cool head. Emotions are superfluous here. If you show unnecessary emotions, you will lose. There is no place for impulsive people in serious gambling, everything must be calculated.
Aside from that, it isn't bad to have a plan for every gambling session. It is one way of gambling responsibly. Planning the time allocation, money to spend on bankroll, and keeping a tab of the time is one of the things we must consider in playing a Casino game.