The best prevention is layered birth control, two different forms like condom plus another method which will increase effectiveness to near 100%.

It’s important to note, for those who need to know it, that “layering birth control” should only be done with different types (ie a condom and a spermicide, or a condom and the BC pill, etc.) It does not mean using more than one condom at the same time! Two or more condoms create friction against each other, which can cause them to tear - defeating the purpose.