The garnishment has to be filled in county clerks office and the paperwork is served to the ex-tenant place of employment.

I've been self-employed for only 6 months, and loans are proving difficult to come by despite my great credit (not to brag, I'm moreso frustrated and seeking help).

When choosing a location for your first rental, it’s great that you’re considering factors like crime rate, population growth, employment rate, and price-to-rent ratio—those are all key metrics.

As a US citizen I have an SSN, file taxes every year on my foreign employment income, hold US-domiciled assets (stocks, IRA, 401k), and I have a ~15 year credit history with a decently high score.

That does not require employment or job seasoning instead it uses the rents to qualify and you can take out up to 80% LTV cash.Use the cash to put down on the next 1-2 or more properties as long as the other properties are debt servicing themselves it opens up more opportuities to buy more future assets and increase your passice income.  

As our team has grown, it's become easier to cover responsibilities if someone quits, goes on vacation, or if we terminate employment, compared to when we had one or two homes. 

Most (not all) HELOCs require that the property is titled to an individual (not LLC) and are full doc, meaning your employment history, income, DTI etc will be factors.

My son (age 24) however, is an independant contractor / self employed and is trying to buy a house. 

For all methods you would want to find a market that has strong employment rates, strong income rates for the market, and is a growing or an established market. 

Look for a location with low crime, then look for the neighborhoods with the best schools.