First Corinthians 6:18 tells us to "flee from sexual immorality." In other words, we are to be absent from sexually tempting situations before marriage. If you find yourself being tempted sexually, follow the example of Joseph in Genesis 39 and do your best Usain Bolt imitation. Run. Scoot. Skedaddle. Make like a plane and jet.
There are some temptations we stay and fight like Jesus (Luke 4:1-13). There are other temptations for which we rely on others who have the temptations in common (1 Corinthians 10:13). But when it comes to sex before marriage, the temptation is often too strong, and the consequences are too steep, so that the way of escape is shockingly simple: to literally escape.
So, keep those sneakers tied! Don't bother to stretch! There isn't time! When you are tempted to engage in sex before marriage, you need to be absent!
Oh, wait, you meant
abstinence before marriage? Well, actually, that doesn't change the answer. Often the best way to stay abstinent is to be absent.