When I worked for the bank I went on decision making course (I still can't decide if I liked it or not
) and to cut a long story short you draw a line down the middle of a page. One side is "For" and the other is "Against". Think of anything related to it and have it weighted out of ten then enter it in the appropriate column.
after 30 or so entries add up each column and see which one has the highest score.
An example. Shall I move to another town.
For - close to the beach 7
Against - I'll miss my friends 10
Against - slightly windy 2
and so on.