Pick a single Pokemon type
Go to http://www.random.org/
Enter a minimum of 1 and a Maximum of 6
Next go to http://www.wyncorporation.com/pokemon/pokemon.php
Set the number of Pokemon to the generated number
Pokemon type to the chosen type you picked to start with
Exclude Legendary Pokémon from results?: set to yes
Final Evolutions/Single Evolutions only?: set to no
You are now a Gym Leader

Print Screen and paste it in to paint, photoreply or reblog with results