Mending (instead of buying new) is SUCH a money-saver... especially for those with kids, because buying a new pair of pants every time my toddler rips a hole in the knees of her leggings would be silly.
Also a huge money-saver: learning to hem and do basic adjustments to your clothing. I had 2 dresses that needed to be hemmed (jersey, no lining - the dresses cost less than 20$ each). The seamstress was quoting me 16$ per dress, which is LUDICROUS. I googled some 'how to hem jersey material without a serger' blog posts and got to work. A half hour and two spools of cotton thread later, I had spent 3$ and hemmed both dresses and saved 29$, while learning a new skill. (and if you already have the thread, you've averaging 60$ per hour savings on sewing... that's pretty phenomenal, when you think about it.)
