1) Always wear clothes that fit. Know your sizes. Start with work clothes and branch out from there. Go to Brooks Brothers for work clothes in Dupont, see the nice old lady there (Susan, I think?) she'll get you fitted. If your buying blind (not knowing what really fits) your wasting money.
2) Don't buy cheap jeans. Have at least a pair or a couple of pairs of Diesels in your closet. Alternatively, G-STAR is ok too. I buy a pair or maybe 2 pairs of new jeans a year, yeah they can run up to 300 or 400 bucks but well worth it.
3) Shoes - Johnston and Murphy is always, always a winner, just don't buy anything with a square tip and your golden. Don't be cheap and DSW, actually go into the store its always a worthwhile experience.
4) T-Shirts are an around the house thing. Don't leave the house in one unless its white and your ripped.
5) Best hidden deals: United Colors of Benetton's Sisley button downs are imho the best fitting off the rack shirts for going out. At the end of each season Benetton has a sale, you can pick these bad boys up for sometimes as cheap as $12!! Hugh and Crye (small company, DC) also makes exceptionally well tailored shirts.
6) Shop the outlets in Leesburg for staples. I took a girl up to Landsdowne resort and we had the best time chilling, golfing, and shopping (and I usually hate shopping). The JCREW store has amazing deals (I bought a crap load of skinny ties there normally $50+ for $5 each for example) and if there ever was a store that manufactures a get laid uniform its jcrew. Socks, button downs, colored pants, etc get your day to day shit there on the cheap.
7) Get your underwear from TJMaxx or Marshalls. They always have Diesel boxer briefs on the cheep and girls really love those.
8) Finally, regardless of your budget think quality over quantity. Better to have 5 complete outfits that are sharp than 100 individual pieces you bought at different times because they were on sale. Set a spending amount and buy all your clothes for the season in one go, you'll look sharper and attract more beautiful women.
Non sequitur: I see posts here about deals and the "cheapest" place to get this or that. Don't think cheap. Cut corners where its appropriate, but invest that time in making more money and meeting more women. I can't believe a real PUA would say "get an outfit from Goodwill" can you really wear clothes that may have been a dead mans? Take pride in your appearance. And if you think women can't tell that your wearing clothes from Goodwill, your wrong, or worse, if she genuinely can't tell, thats pretty trashy and not worth opening your home/bed to.