The first step to getting rid of roaches is to find out where they live. Most roaches live in dark and damp locations, usually out of reach. The next step would be to try to seal the area or put boric acid around the areas see them coming from. When they come from outside, seal all the entrances. Place boric acid around others areas you see them coming from.
Roaches clean themselves a lot.
By walking in the boric acid, they automatically get some on them. When boric acid is ingested, it interferes with digestion and kills them. Vacuum your floors constantly. Roaches detect when food is around. After vacuuming, place a thin layer of Boric Acid on your floor.