Here's some advice from an interview done on mint.com of the author of The Digerati Life blog. It includes an answer to the blogger's top financial tip and also has a financial move that everyone should avoid.
Best Financial Tip:
"... Never take your money for granted. Educate yourself in the areas of finance and business, stay reasonably frugal and invest your savings in index funds..."
Worst Financial Move Ever:
"... Emotional investments in independent stocks. Shorting stocks and participating in overly complicated schemes that involve money. I realized that the more complicated a money making scheme or venture was, the worse my returns were..."
Full interview here