Place the warm shredded chicken in a medium mixing bowl.
Add 1 cup BBQ sauce to the chicken and stir with a spoon or spatula until all pieces are evenly coated.
Split the hamburger buns and, if desired, toast them briefly.
Portion the BBQ-coated chicken onto the bottom half of each bun.
Top each sandwich with coleslaw, pickles, lettuce, tomato slices, and avocado as desired.
Place the top bun on each sandwich and serve, adding extra BBQ sauce if you like.