I actually think BP has made me thriftier, but I might be an outlier. I used to always pinch pennies - now if I catch myself wanting to spend money, I assume it's a symptom and stop myself.

But real tips:
-Couponing used to work very well until everyone figured it out.
-CVS you can get some good deals for free things etc (most of it junk food).
-Not buying gifts/celebrating holidays - did that for the first time this year, was nice.
-Not buying any new clothes for a whole year - did it one year, not as hard as it looks.
-Anything you have basically, especially electronics, can be sold on ebay or amazon marketplace. I sold all of my stuff one thing at a time and didn't even have much nice stuff but made about 5-6k over a year or two. I haven't done it in a couple years but amazon was really easy back then.

Not so good/worthwhile:
-Leaving the heat off if it's winter where you are (I've done it).
-Can write to complain about products and get money back/freebies, especially useful if something was actually wrong.
-mechanical turk - used to use it to do medical surveys or other sites and get paid very little money but can work from home/own hours. i dont think the pay is worth the time, it's really meant for people in developing nations but i used to like doing it.