Don't die? Damn I hate it when people tell me that! I mean, state the obivious!
More useful tip: Its amazing how easy it is to hide behind common objects like boxes and signs. A good example of this is on the Haxor and Weezing River Mall Video - When they hide in the plant.
Same with other things - If the merc is distracted, then a poor hiding place becomes effective. If the merc is unaware, most places are good. If the merc is alert, and serching because he is suspisius, then few hiding places are good.
Helped? No? Already knew that? Stating the Obivious? Yes?
Come on then, spill for more tips for a noob like myself!