Forex is a highly leveraged investment and both profits and losses can be amplified by the amount of leverage used

As a rule of thumb you should not invest in Forex what you can not afford to lose !

New traders should know that the default leverage of 100:1 should never ever be used. Usable margin and Free margin may be terms in Forex that entice you to use additional leverage that can cause you a greater loss. Use 5 to 1 leverage if you are just starting out, this allows to withstand normal market moves against you. Increase your leverage to 10:1 as you become more practiced.

Forexbody suggest using high leverage on very small accounts under $100, Advisable leverage for standard accounts is 10:1 which means that your trade size should be only 10 times greater than your equity size.