Each person's situation is different.
One buyer could be a self-employed individual, another working as an employee for Fortune 500 company, one would not have a website for his business, another would not be able to provide a Certified Public Accountant letter (or your county's equivalent) prepared in a specific way a particular lender wants - and these requirements banks often ask for. As you may guess Fortune 500 company employee is the favorite of the banks. Large banks are tougher to deal with when it comes to foreign national loans because they are not flexible.
However, self-employed people can buy successfully too, if they prepare ahead of time.
You are doing the right thing by starting asking questions re. this process.
I usually recommend to get your specific scenario assessment by two-three different lenders/mortgage brokers. The loan programs these brokers/lenders have constantly change.
I can suggest good mortgage pros for you.
Some banks require to open an account with them to give you a mortgage.
You really should open an account in the US - it is required for the closing and it has to be "seasoned" meaning your funds should be here in the US for 2-3 months.
I also have an international service that helps open an account without your presence here -
which is very convenient, and their exchange rate is very very good.
It is important to be specific when talking to your loan officer. Tell as much as possible about your specific situation - the country you are from, the way you transfer funds from there, if you have a license for the work you do, a website, can document your income etc.
Some mortgage pros joke that a foreign national loan is much easier than that of an American citizen...
Hope this helps,
Beachfront Realty, Inc.