Within a three hour drive, not too touristy, would love a state or national park inn or something similar. About 2 night stay...would love easy hiking or views! Can be beachy or woodsy, don't care!
Big Bear Lake. There are some county parks in Orange County with camping. Other than that maybe Angeles National Forest. The issue with the "not too touristy" areas is lack of accommodations other than camping or limited lodging such as cabins. Since it's so close to Los Angeles, a lot of people just visit for a day and head back.
There aren't too many places that I'd consider "hideaways" in Southern California. If you're not going in the summer then the Palm Springs area is pretty nice. You can go to Joshua Tree National Park for a desert experience, then take the Palm Springs Aerial Tram to see the mountains.
We took a day trip up to Big Bear Lake whilst there in September. I am itching to get back! It was beautiful. I'd love to go and stay for a few days. The drive up was amazing! ( we don't get mountains like that here in Western Australia!!!! ).
If you head down to San Diego, there's lots of hiking here. My favorite is at Torrey Pines Stare Reserve. It's an easy hike up a mountain and then down to the beach. Amazing views!