To avoid losses traders have to be extremely short term.
To trade without knowing anything about what is going on, you have to assume that any movement against you is going to carry on going against you in the most painful way it can. This isn't too drastic of an assumption, as anyone that's held onto a losing trade only to see it get worse and worse will agree.
Without any knowledge to the contrary you have to assume the worst, and the only protection against this is not to be in harm's way: The less time you're in a position, the less can go wrong.
Take your profits quickly and your scratch trades and losses even quicker. By quickly I mean instantly, profit scratch or loss you should be out, or at least have your counter trade in, within 10 or 20 seconds at the most