Originally Posted by motorbreath
My neighbour scared me off of them, he said that for heavier trailers they tend to sink into the ground since they are more narrow than the blocks. Is that true? I would definitely prefer them over the blocks.
Get some 3/4" pressure treated plywood and make a base for each side of the trailer that is long enough span the length of the area the tires set on plus the length of one of the levelers plus a bit added to ensure you won't roll off the end of the base. Make each base as wide as you feel you would need to avoid sinking into soft ground. It wouldn't hurt to bevel the ends but 3/4" isn't all that much of a bump for trailer tires.
Just throw down the bases behind the tire, back up onto the bases until the forward tire is barely on the base, position the levelers on the low side of the trailer, then finish backing up until you are level. If the levelers slide on the bases, stick some antiskid tape onto the levelers.