[header] How to avoid strange people [title] Avert your eyes. [step] Averting your eyes signals to the other person that you are not interested in a conversation. Even if the other person has already engaged you, a slight diversion in eye contact can signal to them that you do not want to continue the conversation. 
[substeps] The rest of your body language can also play a part. Angle your body away from the person and cross your arms or look down.