1. Launch a war you intend to win, like WWII  not Vietnam. Not to just control or negotiation.
"But Daniel purposed in his heart that he would not defile himself with the portion of the king's meat, nor with the wine which he drank: therefore he requested of the prince of the eunuchs that he might not defile himself." Dan 1:8

We have cultivated many weed in the Garden of our thought live. In our imagination and daydreams. Satan tell you that it is hopeless and enjoyable and God will forgive. Someday maybe when life is easier less pressure.... We must put our will to the strain, to purpose to win. God will combine his power with our effort. Begin the weeding -repenting. Plant ground cover (i.e. meditate on God's word). We don't weed our thick ground cover.

We cannot discern the character of God, or accept Christ by faith, unless we consent to the bringing into captivity of every thought to the obedience of Christ. To all who do this the Holy Spirit is given without measure.

2. Our prayer should not be to take a our desires, for God gave reproductive instincts. Our Prayer is to take away impure thoughts and desires. Pray that God will cleanse our Imagination.
"Wash me thoroughly from mine iniquity, and cleanse me from my sin." Psa 51:2  

3. Make an agreement with our eyes. Look away from seductive pictures and people.
"I made a covenant with mine eyes; why then should I think upon a maid?" Job 31:1  

4. Satan is Manipulating people or circumstances to ambush us. Be aware lest we wonder near the tree of Knowledge of good and evil.
"For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places." Eph 6:12  

5. Remove from our environment that which contributed to our defeat. worldly music, TV etc.
"But put ye on the Lord Jesus Christ, and make not provision for the flesh, to fulfil the lusts thereof." Rom 13:14  

6. To win the war we must fight many battles.
"If thou hast run with the footmen, and they have wearied thee, then how canst thou contend with horses? and if in the land of peace, wherein thou trustedst, they wearied thee, then how wilt thou do in the swelling of Jordan?" Jer 12:5

Someone may "spit in you brain", at work dirty stories are frequently told. We must communicate that they are not appreciated or it will continue and haunt you for the rest of the day or for a lifetime. 

7. Live in the fear of the Lord.
."And unto man he said, Behold, the fear of the Lord, that is wisdom; and to depart from evil is understanding." Job 28:28  God is here always the angels are here. Less tempted with the brethren around 

8. Claim the victory
"Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof." Rom 6:12