Combine the shrimp, olive oil, lime juice, garlic and chili/cayenne in a bowl. Allow it to sit and marinate for about 30 minutes. I let my shrimp marinate for about 4 hours covered in the refrigerator - it was pretty flavorful!
Cook your shrimp however you wish - grill, saute, etc.
In your food processor, add the jalapeno, the ranch dressing and the sour cream. Blend it all together until completely smooth.
In small bowls, offer shredded cheese, diced tomatoes, the jalapeno ranch sauce, diced avocado and shredded lettuce to go with them.
Warm the tortillas and allow everyone to assemble their own with whatever additions they want.