I never once in my life woke up in the morning and said: I am glad I drank too much alcohol last night.
I never once in my life woke up in the morning and said: I wish I didn’t work out yesterday.
As a general rule, you know as early as just one day later, what you did yesterday was good or bad.
Actions such as working out, eating healthy, practicing to play an instrument, studying, working on your business, reading a good book, eating at home, approaching girls, saving money, making a to-do list and so on, lead to happiness and pride the next day. You feel it in your gut that you are progressing towards a better future.
Actions such as watching TV, playing video games (especially when you need to study or work on your business), wasting time on social media, drinking alcohol, smoking, doing drugs, eating junk food, watching porn and so on, lead to regret and self-loathing the next day. You feel it in your gut that you are shooting yourself in the foot.
Delayed gratification is not so much delayed, after all. You start to feel the glimpses of gratification as early as the next day.
Therefore, it’s a good rule of thumb to ask before engaging in any activity today: How will I feel about this tomorrow?
If you are sure that it will make you feel good tomorrow, then do it.
If you are sure that you will regret it tomorrow, then don’t do it.
Keep in mind that when you repeat actions for long enough, they become habits.
If you apply The Tomorrow Rule to your actions, you favor acquiring good habits and prevent forming bad habits.