Many accounts were blown up in the recent market crash and the main reason was cross-margining.

Most people don't even know the difference between isolated margin and cross margin.

In isolated margin, only the amount you put into that trade is settled if things go wrong.

But in cross margin, the entire balance of your account is at stake, you are basically risking everything in a single trade.

If you are new to trading, not yet profitable, or really don't understand how margin works, I wouldn't recommend using leverage at all.

But if you really want to, at least stick to isolated margin, that way, if the market suddenly drops, you only lose what you put into that trade, not your entire account.