We all have a home which consists of at least two rooms, hall, bathroom and kitchen and thieves can steal any of our homes so we should take advantage of this, let me tell you my idea: you can go to the homes of peoples who don't know how to defend themselves if a thief broke into any part of the home. You can make them know the suitable tools which they should use in every part of the home and the suitable ways which they should do in every part of the home rooms, hall, bathroom and kitchen.
Note: you should be an expert in the ways of self defense to take this idea. I think that this job may make your income increase.