We've all been in that position where we just REALLY don't want to do something. Instead of simply telling the truth, we somehow convince ourselves that an unnecessarily elaborate excuse will spare someone's feelings or make us look better. Whether it be to avoid school, work, a meeting, or just hanging out with that person who thinks they're your "best friend," you've definitely used these excuses more than you'd like to admit.
1) You're too tired.
2) You're too broke.
3) You've contracted some rare disease overnight.
4) You have a doctor/dentist/some kind of crucial appointment.
5) It's too hot.
6) It's too cold.
7) Your parents said "no".
8) It's your birthday.
(Or your mom's, sister's, or long lost cousin's, whatever works ... )
9) Your car broke down.
10) You already have plans.
11) You have an important "family event".
And of course, the famous ...