Create a coastal-inspired garden oasis by combining DIY windmills made from reclaimed materials with vintage beach decor. Use weathered driftwood or old boat paddles as the windmill blades and attach them to a sturdy metal pole. Surround the windmill with seashells, starfish, and nautical ropes. Plant beach grasses, succulents, and coastal flowers like hydrangeas and lavender to complete the coastal vibe.