I recall my mom telling me as a child not to use the word "should". For instance, I might say: "I should bring an umbrella because it's going to rain". But she would say: "no, you want to bring an umbrella, because you want to keep dry, and you think an umbrella will help with that. God doesn't care if you bring an umbrella. Only you care."
I've since generalized this as follows:
Instead of "I should" or "is good", I generally use "I want".
Instead of "is true" or "is correct", I generally use "is useful".
Incidentally, I'm not sure why my mom told me that, since she is religious, and "should" seems like a common word in religion. And my generalization is even worse from a religious point of view, because it suggests that God isn't real so much as convenient.