Preheat your grill or grill pan over medium-high heat.
In a bowl, combine olive oil, smoked paprika, garlic powder, cumin, salt, and black pepper. Add the shrimp and toss to coat evenly.
Thread the shrimp onto skewers for easy grilling. Grill the shrimp for about 2-3 minutes on each side, or until they are pink and opaque. Remove from the grill and set aside.
In a separate bowl, mash the avocado with lime juice and salt until smooth. Adjust seasoning to taste.
To assemble the tostadas, spread a generous layer of the avocado smash on each tostada shell.
Top the avocado with grilled shrimp, cherry tomatoes, red onion, and chopped cilantro.
Serve immediately with lime wedges on the side.