To keep the trailer from wiggling, we use a BAL single axle wheel chock on each side. If I didn't already have them, I would have purchased a BAL chock for dual axles.
BAL wheel chockshttp://norcoind.com/bal/products/consumer/chocks/chocks.shtml#single
To keep the trailer level & stable, we stack blocks under the jacks so the scissors don't extend more than halfway. We tighten snug plus about 1/2 turn and recheck after the tires cool down.
Dave