Under capitalization (i.e. a small trading account that only just covers its required margin) can be one of the biggest problems that new traders face. However, with the right risk management techniques, a small account can be traded profitably, and can eventually be turned into a large (i.e. well funded) account.
There are several risk management techniques that should be used for all trading accounts (regardless of their size), but especially for small trading accounts, where the buffer against losses is minimal. The most important risk management technique for small trading accounts is the one percent risk rule, which states that no more than one percent of the trading account should be risked on any single trade.
Whether you are trading a $1,000,000 account, or a $2,000 account, my article about trading a small account offers advice for trading under capitalized accounts, and details three risk management techniques (including the one percent risk rule) that can be used individually or combined into a complete risk management strategy.