1.Not eating at the monitor
2.Removing all food and scraps immediately
3.Traps: non-chemical adhesives, bottles and cups with water spiced with vinegar(2-3 drops)
4.Autism: Just declare exterminatus and kill them manually all day in spare time.
5.Never invite exterminators or use anything chemical or ultrasound. Your liver will thank you later.
6.Cockroaches are not as big of a problem as rats. Consider yourself lucky.