If using wooden skewers, remember to soak for 1/2 hour; or place in microwavable container, cover with water and microwave for 2-3 minutes until pliable.
Also, use *two* skewers per kebab not just one. It helps when turning the kebab over, so the sausage and shrimp don't spin uncontrollably like a weathervane... as they would if using only a single skewer.
Experiment with any variety of small (diameter) sausages for a different flavor (i.e. Boudain from Louisiana works great; or chunks of Bratwurst or Mettwurst from Milwaukee!).
Bon Appetit avec cuisine en minceur !