Fill a rimmed plate with warm water and dip sheet of rice paper into the water, ensuring all is submerged, 3-5 seconds. Place wet rice paper sheet onto a flat surface and fill the bottom half with tempeh, bibb lettuce, avocado, and cucumber. Be sure not to overstuff, and leave about 0.5-1 inch of space on the bottom and sides for folding. Tuck in the sides of the rice paper and roll the rice paper away from your body to form a burrito shape. Continue this step until you’ve used all the rice sheets.