We're planning on some variation of the "Robinson Curriculum" (http://www.robinsoncurriculum.com/), which in essence is a simple daily structure of (1) a daily math lesson, from the Saxon math series or similar, (2) daily reading, based on their interest but with a few recommendations, and (3) daily writing about any topic that interests them, which is then proofread and corrected by the child.
"Socialization" is pretty much a non-issue, as far as I'm concerned. The above structure takes a few hours a day, so there's more than enough time for play and structured activities like sports or music if they're interested. As tommynazareth commented, the socialization in schools is mostly negative.
The key seems to be striking a balance between a clear and simple structure and letting your child follow their interests. It also requires some self-control by the parents - it's better to let your kids struggle at times when they find hard problems than immediately jump in and help them. The parent isn't doing the teaching - they're helping the child learn to self-educate, which is a major difference.
I want my children to be able to think clearly, learn essential skills, and be able to teach themselves anything they're interested in learning. I don't believe the public school system is capable of doing that, which is why we're looking to do it ourselves.