The practice of making today a good day isn't something you do right before bed when you give the day a score and pack it away. Making today a good day is about being where you are; being here, in the now, recognizing that you are making the day a good day.
Not every moment of every day is going to be good. Most will be average. Some moment will be frustrating. Some may make you sad or angry. The goal is to recognize and accept and not wallow in those moments. The goal is to not get into a loop where those moments ruin a day.
An amazing by-product of praciticing making today a good day is that you will notice more good moments. Your average moments will be better than many others. Your frustrating, sad, angry moments will be balanced with the knowledge that they aren't the only thing that makes up your life.