Fill a wide, shallow bowl or casserole dish with warm water. Place a clean kitchen towel next to it on a work surface. Submerge 1 spring roll wrapper into the bowl for a few seconds until it softens. Gently transfer it to the towel, laying it flat. Dip a 2nd wrapper into the water, then lay it on top of the first one. Use a clean towel to gently pat it dry. Place a lettuce leaf on top of the wrapper, then top it with some basil and mint leaves. Arrange a small line of shredded carrots, a few slices of cucumber, and some avocado. Be careful not to over-fill. Lift the bottom edge of the spring roll wrapper and fold over the filling. Fold in the sides of the wrapper and roll to form a tight roll. Place on a platter with the seam facing down. Repeat with the remaining spring roll wrappers and vegetables to make 10 rolls.

Slice each summer roll crosswise in half, and serve with your favorite dipping sauce.