How does one choose one thing over another? It comes down to what our priorities are and what we hope to achieve.
If our ultimate goal is to lose weight then the obvious choice is to not eat at McDonalds.
If we want to get good at a martial art like Aikido then the obvious choice is to go to class.
The hardest part is when we forget in that one moment what our goals are. This is why experts recommend that we constantly review our goals throughout the day as a reminder and review them just before going to be and as soon as they wake up. Reviewing them many times throughout the day enables us to remember and if we schedule it just right then it helps us stay on track. Reviewing them in the morning and at night enables our goals to sink down into the subconscious layers of our minds where our goals can be put into play within our minds.
It is said to take 21 days to create a habit and 90 days to create a lifestyle. This only works if one is "doing" it for those 21 or 90 days. Any day missed can lead to one losing their way. This is why it is important to review them regularly and in the morning and at night. Our minds cannot differentiate between conscious action and sub-conscious thought. Therefore if one is able to put time into just affirming the goals in their minds regularly and in the morning and at night then the 21 days are easy to arrive at.
Anything is achievable with action but just about impossible with inaction. Don't wait. Think about your goals regularly and choose to be better.