I would say by reading the Bible and if we lack faith, then by praying for God to help give us faith. Sometimes he's the only one that knows how.
Another practice, I believe, is by making sure that you have the armor in Ephesians 6 to block whatever is hindering your faith.
Ephesians 6 13-17
Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand. Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place, and with your feet fitted with the readiness that comes from the gospel of peace. In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one. Take the helmet of salvation and the sword of the Spirit, which is the word of God.
Just like if you're under spiritual attack, you fight back in the same way Jesus did in the desert. He didn't argue with Satan. He gave us an example by quoting scripture (that is your sword) until Satan left him. "Submit to yourselves, then, to God. Resist the devil, and he shall flee from you."