"Final Attack Orders" can be used so "Dream Clown" will be switched to attack mode.
"Mist Body" can be used to protect "Dream Clown" long enough for it to use its effect, as well as "Heart of Clear Water"
Using cards like "Zero Gravity" can help you destroy a monster during your opponent's turn.
Equip "Dream Clown" with "Spirit Burner" to increase the rate at which you can change it's battle position to Defense position, thus activating it's effect.