Don't heat food in plastic in the microwave. Put in the effort to put it in glass or a plate or so, then heat.

Don't store hot leftovers in plastic.

Don't buy and drink plastic bottled water.

If you can in the stores in general chose between food and drinks packaged in glass or cardboard vs anything else: chances are glass or cardboard packaging is the healthier choice. Aluminum cans should still be okayish too, tho they possibly layered it with plastic inside too depending on the pH of the contents to slow down reactions between can and product.