I probably won't do the following:
1) Sign up for credit cards. I've had 3 so far, and I don't plan to get any more.
2) Manufactured spend. Don't want to get banned by any banks!
3) Book a "throwaway" hotel room just to complete a promotion
4) Do low-yielding surveys. Some surveys are worth it, most are not.
5) Open hotel accounts for my folks and have them book rooms for me to earn a promo.
6) Mileage runs. The cost in terms of time and wasted productivity is too much.