Spot foreign exchange (exchanges of foreign currencies) brokers - They do not charge any commissions because they make profits from the bid/ask spread quotes. On July 10, 2006, the exchange rate between Euro and United States dollar is 1.2733 at 15:45. The internal (inter-bank dealers) bid/ask price is 1.2732-5/1.2733-5. However the foreign exchange brokers or middlemen will not offer the same competitive prices to their clients. Instead they provide their own version of bid and ask quotes, say 1.2731/1.2734, of which their commissions are already "hidden" in it. More competitive brokers do not charge more than 2 pips spread on a currency where the interbank market has a 1 pip spread, and some offer better than this by quoting prices in fractional pips.
Assess how much capital you're willing to risk on each trade. Many successful day traders risk less than 1% to 2% of their account per trade. If you have a $40,000 trading account and are willing to risk 0.5% of your capital on each trade, your maximum loss per trade is $200 (0.005 x $40,000). Set aside a surplus amount of funds you can trade with and you're prepared to lose. Remember, it may or may not happen.