I live in San Diego but took a job in Los Angeles as an independent contractor with a 1099. I stay in LA 4 nights a week and spend the weekends in San Diego where my home office is. I understand that I can deduct my living expenses and meals, but I was told that I can use the GSA per deim guidelines for Los Angles instead and not keep track of my expenses in LA. I have my own LLC. How do I go about doing this?

The IRS per diem rates can be found in IRS Pub 1542, which can be downloaded from Internal Revenue Service.