It'll sound counter intuitive, but one way to avoid problems with oxalates is to consume calcium rich foods with oxalate high foods. For example, a glass of milk (soy milk counts) with a PB&J.

The reason this works is the calcium binds with the oxalate in your stomach and not your liver/kidneys.

For this to work, you have to consume both at the same time.

Something that's always stuck with me (re:kidney stones) is that consistently sleeping on the same side seems to increase the likelihood of developing them.

In the 93 patients [of 110] who consistently slept to one side, the side in which renal stones were found was identical to the dependent sleep side in 76%. source