I think an important pre-skill is to decide what your goals are BEFORE checking the consequences. Otherwise, you can easily retroactively change your goals to fit whatever action you want.

For example, in the sunk costs PhD scenario, it would be easy for someone to say something like "If I pursue my PhD, it will make my family proud. This is very important to me, so I will pursue my PhD." However if you asked them what their goals are BEFORE they listed the consequences of each action they probably would not list "Make family proud", but would list things like "Job I enjoy" and "Make more money in my career".

The trap is that it can be very difficult to admit to your ACTUAL goals. For example, it took a while for me to realize that I don't ACTUALLY care about making money once I have enough to survive (unless phrased in a way such as "If I do Job B, I only have to work 12 hours/week" or somesuch).

So I think figuring out what your actual goals are (noit the cached thoughts of your goals) is a set of exercises itself, but that they should probably be done before the Consequentialism exercises.