For a thicker consistency, use milk kefir that has been "dripped", or the curd-like part separated from the whey. Alternately, play with the mayo to kefir ratio until it meets your favorite consistency.
Swap any favorite herbs and seasonings to add variations, such as red pepper flakes for a little kick.
For a chunkier recipe, our family loves to add shredded chicken, diced celery and cucumbers, or sprinkle in parmesan cheese (not strict gaps).