Riding around with a trials gear isn't easy. It calls for a unique technique. What's yours?
An even pressure on the pedals as you rotate them technique is much more tiring. Pedal, pedal, pedal, freeeeeewheeeeeeel, pedal, pedal, pedal, freeeeeeeewheeeeeel.
I go for starting with the pedals up and down (vertically) and stamping on the pedals one at a time. So, right foot stomp (Charlie Brown), freewheel, left foot stomp (kriss-cross) freewheel. Repeat.