We we're lucky to stay two weeks with our friends in Mission Viejo within the Orange County. 
Here are some things to do while spending some time in Orange County.

Sidecar Donuts, Costa Mesa (!!) 

Irvine Spectrum Center
, Irvine
South Coast Plaza, Costa Mesa
Fashion Island, 
Newport Beach

Beaches, beautiful little cities:
Huntington Beach (famous for surfing)
Laguna Beach (cute little city)
Newport Beach (grab a coffee and walk over the "famous" pier)
San Clemente (stunning beach walk)
Dana Point (go for "boat" watching at the harbor)
Oceanside (already in San Diego County - everything is less expensive than in OC)

Ask for Ryan at American Vintage Tattoo in Orange or go Newport Tattoo in Costa Mesa.

The crab cooker (fishy fish)

Newport coffee company
right in front of the Newport pier. they serve tasty coffee for reasonable prices and using Stumptown beans! nice place for grabbing a coffee and strolling along the beach!