Listen to and study various crunk artists such as Lil Jon, Paul Wall, Mike Jones and Chamillionaire. Try to find a commonality among these various artists. Even though they create an array of different songs, you'll find that many of them use slower to moderate tempos and high-pitched synthesizers.
Download and install a beat making software program such as Fruity Loops or Sonic Producer.
Begin creating a loop (or beat) by creating a new project in your beat maker program. Select a tempo (start around 90 bpm and work your way up from there, if necessary), and then select a drum kit sound. Begin looking in the hip-hop sections for the drum kit you want to use.
Fill in different boxes by clicking on them. Each filled-in box represents a sound. For instance, if you fill in the boxes on the one and three beats with a kick drum sound and the two and four beats with a snare drum sound, you will have a very standard one, two, three four beat. Experiment with different patterns and different sounds to create more unique beats.
Choose a bass guitar sound and repeat the previous step.
Choose a synth sound, such as a sawtooth lead (gold saw) or other electronic sound to create your crunk lead. It's this sound that will take your beat from hip-hop to crunk. Tweak the high equalizer level on the synth sound by right-clicking the selected sound, then clicking "EQ." Turn up the high EQ and turn down the mid EQ to get that crunk sound.