If you have at least 2 years of tax returns with good credit, then there is not a whole lot of difference compared to the salaried/employed people. You will still need to come up with all the remaining requirements but the 2 year tax return is a must.
If you have less than decent credit or have very unpredictable income it can be a little tougher, but there are secondary and private mortgage markets to help there and while more expensive they aren't horrible, but a little more buyer beware. I have used this market before for income properties and you will find that there are assholes that try to take advantage of you because they think you are desperate. Then there are those that are there to make a good return but are totally reasonable. If you have to go this route, find a mortgage broker that deals in this market, it isn't that hard and a reputable one will help keep you out of trouble.
EDIT: BTW -- debt to income ration is a little more important here depending on the type of debt.
"[10:19] Mike: When I first started out, I did have a mortgage and to be perfectly honest, if you have a mortgage already, it’s a lot easier to quit your job than it is to quit your job and then go get a mortgage just because the sheer amount of paperwork that the bank will send you in order to get a mortgage if you’re self employed is just astounding. You’re much better off just going and finding someone to pay them to hire you at whatever salary you want and in order to be on their payroll instead of having your own just because banks have this thing about you’re self employed, you’re risky. And it’s like you’re probably making decent money in order to be able to do that."
Most of the financial forms now ask if you own more than X% of a company (I think 10-20%), and you must list which one if you do. Plus you sign an IRS form that allows them to pull your prior tax returns, in which case they will likely see the corporation or partnership forms, meaning you just lied to the bank. While rarely is it prosecuted and rarely do you get in any real trouble, it is technically against the law in the US from what I understand. And if nothing else, bad way to start off with the bank.
There are the rare cases like remyp mentioned where you are an employee but own a reportable percentage of a company in which case you still have to disclose it all up front to avoid banks from getting all crazy on you.
You can search for a lot of the rules as many fall under the dodd-frank mortgage rules, and also you can look at the fannie mae guidelines as most banks follow them to protect themselves.
This assumes you don't mind having and being a landlord at the same time.
