Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

@Mario MoralesI think this is a common question and the value that an agent will bring will vary by individual needs.

After every negotiation, reflect on what went well and what could be improved.Negotiation isn’t about “winning” at the expense of the other party—it’s about finding common ground where both sides feel satisfied.

They are far more common now and harder to find models without but:1) these add cost to the purchase price2) they don't bring a lot of value3) they can leak or detach and damage the propertyI own around 50 doors and I cap off the line at the wall or in the basement with a valve and a cap so the potential for leaks is 0.00001% :-) 

How will you do so if you are W-2 employed?

@Phil SheltonYou would need a civil engineer to provide a drawing to get submitted to zoning and get a permit if it passes zoning is most common This also depends on the road - if it’s a state road forget it as it will take a year to get approved and cost a fortune - if it’s a local road process not as cumbersome but don’t expect this to happen quicklyIn some instances you may have to prepare sight distances etc to make sure it’s safe to add a curb cut

And with much more in commonality with starting and running say a restaurant. 

In areas like Frisco, Plano, or Arlington, proximity to major employers and universities like TCU or SMU can make a big difference.Stay Curious and PersistentReal estate investing is a marathon, not a sprint.

Real estate's "gross rent multiplier" is Wall Street's "sales to revenue",  "cap rate" is roughly "P/E ratio".When evaluating markets and investments I tend to start with GRM (or lazily the 1% rule), then attempt to return a cap rate based on assumptions about costs, then I work my way to multiple years of projections (assumptions about inflation, amortization, tax benefits, etc), and if I am partnering with one of my smart friends I have to pull up an IRR (internal rate of return).I also look at regional employment levels, median income to rent ratio in the zip code etc. 

Sales comparison A common method that compares the property to similar properties nearby and their relative prices.