I've been asking myself the same question. Many moons ago I learned of a "Blanket Mortgage" but when I ask lenders they ask me to explain it: One mortgage but multiple properties are collateralized.
So then I asked if I could do two loans at once, do a cash out refi and use that cash as a down payment on a purchase mortgage and was told that can be done, it's not often but it's not unheard of. What I like about that is that it could be done on the same credit report, instead of multiple reports which dings a few points.
As far as counting rental income to boost your debt to income (DTI) ratio, I've been told that they cannot count projected income, only actual income which usually means that the income must be on TWO tax returns. This means they don't care what the rent is going to be despite how clever or convincing you are. They want the track record of being an effective landlord. They just average the last two years' income for the DTI, regardless if landlord or not. Maximum DTI is 45% usually. This is why I like many others look at hard money options when getting started just to get two good tax returns. In other words, the more taxes you pay, the more you can borrow from banks/credit unions.
I've heard of loans where the underwriter accepted one tax return and used that for the DTI, and the borrower got the loan. This was a mortgage broker, not a banker/credit union.
It appears to depend on how hungry the particular lender is to loan money, and if you have 700/720 credit and six months' of reserve payments on all loans (but you can use IRA money to show that).
I've been told that the LLC entity can borrow money on properties, but that all members of the corp must qualify, meaning each member must have DTI under 45%. I've also been told that lenders get real scared or confused when the title is held in any kind of trust. If an LLC with members that use their own cash to fund deals, then the $#@#$ing gift letter is unnecessary.
As always, my experience is local to Central Florida. Secondly, like Kiyosaki states, I don't know what I'm assuming. I do find that the more lenders I interview, the more assumptions I find that have cost me money.
I've learned on this forum that there are lenders that will do these deals but I am going to have to start calling around to find them.
I keep saying 'I heard this' because I'm just getting started investing after 19 years as an appraiser. My strategy is buy and hold, to replace my income first before I start flipping. I stay away from hard money because those lenders want an exit strategy; refinancing with a vanilla mortgage is not a solid exit strategy because who knows what the banks are going to require next? Secondly with hard money people I've interviewed, I'm limited to 50% of purchase price, not After Rehab/Reno Value (ARV) or appraised value.