How to make 100 different NPC's

Let's say your larp consists of 20 players (on a good day). You have a budget of whatever you can scrape together. You have some basic skills, such as building weapons, simple sewing, basic construction... But with limited garb and resources how do you make varied NPC's? How do show the players what monster they face with verisimilitude and without expensive garb? How do you make that disposable hoard come to life? Here is one simple thing you can do to make 100's of NPC's, with the basic skills you already have.

Current Gear

Here's a look at my garb and armor at the moment. Let's walk through each piece, and take a look at each. There are pros and there are cons to the look and the use of each item and there are plenty of areas where things can be improved. All this can be found in this gallery, if you just want to see the pictures. Tons of pictures below the jump!