Thread the vegetables onto the soaked skewers in an alternating pattern. Brush with 1 tablespoon olive oil and season with salt, pepper, garlic powder, onion powder, and dried oregano.
Preheat the grill to medium-high (around 400°F) and lightly oil the grates with remaining olive oil. Grill the skewers for approximately 3-4 minutes per side until tender and lightly charred.
Serve with a squeeze of fresh lemon if desired.