Don't let them be set by others (except of course when your job is defined that way; but even then this only holds within sub-priorities of the personal priority of 'doing your job').
have 3 alternatives
sleep on it
Projects require all three of these things, but they require more acting than talking, and more talking than thinking. Make sure you don't neglect any of them.
http://spacecraft.ssl.umd.edu/old_site/academics/akins_laws.html
founders are 'do-ers'
in a startup, nothing happens except when someone makes it happen