Preheat your oven to 400°F and place the corn tortillas on a large baking sheet.
Lightly brush both sides of the tortillas with half of the olive oil and bake for 4-5 minutes per side until they are golden and crispy.
In a medium mixing bowl, toss the raw shrimp with the chili powder, cumin, sea salt, black pepper, and the remaining olive oil until evenly coated.
Heat a large non-stick skillet over medium-high heat and sauté the shrimp for 2-3 minutes per side until they are pink, opaque, and slightly charred.
In a small bowl, toss the shredded cabbage with half of the lime juice and the chopped fresh cilantro to create a bright, zesty slaw.
In a separate small ramekin, whisk together the non-fat Greek yogurt and the remaining lime juice to make a light lime crema.
To assemble, place the crispy tortillas on a plate and top each with a generous portion of the cabbage slaw.
Divide the sautéed shrimp between the tostadas, top with thin slices of avocado, and drizzle with the lime-yogurt crema before serving.