If you want to give your credit card some exercise, head out to Oberoi Mall in Goregaon East. Why not take a stroll along the beaches and watch the sunset while you're here? It's also full of great shops and restaurants, so you can spend the afternoon having a wander.
Explore the great outdoors at Chhota Kashmir Park, a lovely green space in Mumbai. Wander the forest or discover the area's sunsets.