Revelation 12:12. Woeto the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.
Ephesians 6:14-18.
14 Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place,15 and with your feet fitted with the readiness that comes from the gospel of peace. 16 In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one.17 Take the helmet of salvation and the sword of the Spirit, which is the word of God.
18 And pray in the Spirit on all occasions with all kinds of prayers and requests. With this in mind, be alert and always keep on praying for all the Lord’s people.
I also think on top of having prayers, one should be prepared to serve God and accept Jesus as saviour. It’s one thing to be exorcised of demons and another thing to break demonic altars completely.