What's the best way to keep insects out of your house...?

Keep the house clean! when i moved here in my apartment a few months ago, i noticed that there are some big cockroaches crawling specially during the night. The owner told me, the previous tenants were a family. Anyway, what i did was i bought a spray for cockroaches and sprayed on corners specially in the kitchen or where they usually thrive before sleeping. I also make sure that waste bins are tightly covered so it won't attract cockroaches. Dishes should always be washed and kept from the sink. make sure, there will be no food left or scattered anywhere to feed those pests. If u see one, don't ever ever try to kill by smashing! use the spray. Hope this helps.