This is the Game Master (AKA "GyrMaster") homepage. Here, you'll find GM tips, articles, and ideas. Most of this is intended for experienced GMs, but I'd encourage novice GMs to give it a go...
Before you show your Explorers an illustration of a monster that they are about to encounter, describe what they see. Give them hints; the smell of the monster's sweat, crackling underbrush, creaking floors. After they've made a mental picture, show them!