Book a hotel in the area if you can! Even though the Metro system in LA is really good (there's a train that goes directly into Santa Monica!), you'll be able to enjoy the area much more if you're staying nearby. Plus, there's so much to see and do that you'll wish you would've stayed in the area.
Rent a scooter or bike. We didn't do this but saw SO MANY people on them. They rent for around $7 USD an hour (or $20 USD a day), and can get you from point A to point B in a fraction of the time. Did I mention that the scooters are motorized?? You'll get to Venice Beach in 5 minutes!
Walk the Third Street Promenade. If you like shopping (like me!) then this is where you want to be. Our credit card definitely took a hit when we went here. π³
Ride the Ferris Wheel on the pier. I know this sounds like a no brainer, but just make sure you do it! I'm terrified, and I mean TERRIFIED of heights, but I made sure to do it. I had my eyes closed for most of the ride, but when I did open them the view was incredible! :) $10 USD per person.
Jen π·