Since you prefer organic techniques but are willing to try conventional pest control if necessary, look into IPM (integrated pest management). Their philosophy is basically the same. Here's an IPM article for California:
And some more general articles:
It seems there is a generation of squash bugs that survives through the winter and starts feeding on plants in the spring. These lay eggs in spring, and the babies feed on plants for the rest of the growing season. So these guys will always be around.
Cucumber beetles hatch or fly into an area in waves, and there are six species, so these can appear at various times. These are unfortunately difficult to control, although natural predators or carbaryl-based insecticides may work. Some people reccommend vacuuming them up. Sticky traps or attractive traps intended for beetles may work and can be purchased at gardening stores or made at home.