And when in escrow, a far away realtor will not meet your inspector, but have the listing realtor to do that, possibly influencing the negotiation process (hearing/seeing the issues before you get to know about them). 

My advice for new agents is that the first thing you should do is to tell everyone in your SOI (sphere of influence) that you are an agent.

I have been basing my business of of my sphere of influence no results so far.

That might influence part of where you want to invest. 

Public schools, in large cities, are too political and the children are too easily influenced.

Thousands of records, some of which aren’t accurate or no longer reflect a tenant’s financial situation, won’t easily pop up and influence landlords or other screeners, said James Mackey, an attorney with the Legal Aid Society of Columbus."

This is a huge range, and would greatly influence cashflow.

Do not buy a deal to buy a deal (impatience and wanting to jump in the game), do not rely on other people's numbers (agents/brokers influencing you to buy), and ALWAYS stay true to your analysis.

I think the go getters and the strong are influenced by the doubt from others, while the weak give in and believe the doubters. 

There is really no magic to it...anything beyond being prepared and having your house completed/in order is probably undue influence as the appraiser is supposed to act independently and all data must be supported by market trends and comps.