If I plan a repeat C-section, how can I make it as safe as possible?

Schedule the C-section after the 39th week of pregnancy if there is no urgent reason to give birth sooner: Babies born before the 39th week of pregnancy are more likely to have breathing and other problems.
Use epidural or spinal anesthesia. Regional anesthesia (you are numbed from your ribs down) is safer for you and your baby than general anesthesia (being "put to sleep").
Request antibiotics before the C-section incision. Antibiotics reduce the chance of infection. You do not need them afterwards unless you develop an infection.
Request care after the surgery to reduce the chance of blood clots. Depending on how likely you are to have this problem, you may need to get up and walk soon after the operation, wear elastic support stockings or mechanical leg compression devices, or take medication to prevent blood clots.