I would say spending too much on an opening order and putting it on a credit card. (ouch!). I now choose only companies that have no minimum and pay cash/debit card. Im a cash only business now. (well of course my clients can pay with credit cards, which I do through PayPal. No more cc terminal to rent for outrageous amounts, or merchant account and statement fees and all that crap I paid for before! No more!). In general I'm much smarter about how I spend my hard earned dollars.