It has everything to do with discipline, if you are not disciplined enough to eliminate bad debt before you being to save for and start investing you will not likely have what it take to succeed in life. 

Glad you have the spending discipline, but need to earn and save some money like @David Faulkner mentions.  

It's always "cosmetic" plus new doors or "cosmetic" plus appliances, roof & furnace, etc.We use a simple, manual spreadsheet with ball park pricing for each of the rehab disciplines.  

Of course, you will have underwritten the deal at sufficiently conservative financing rate - like the BoC posted 5-yr, fixed-rate reference - that the business easily throws off cash at the actual financing rate.If you are disciplined enough to apply the "cash-back" directly to the mortgage principal as a pre-payment (some lenders will {strongly} encourage this approach) it is a good thing ... if you use the cash-back on a rental property financing to pay-down the principal on your primary residence (where mortgage interest cannot be deducted as a business expense) you may warrant extra kudos.If you are certain you can re-invest the cash-back and earn a higher {net} return than paying down your mortgage financing {particularly that on your personal residence which is paid with after tax income}, the cash-back can be a good thing.  

I am not saying that this is the best way to go as i am not following this method myself, but it is the way I imagine it would go if I were interested in doing so and disciplined enough not to spend the income from the rentals.  

There are sacrifice and discipline in saving money and building credit and through those sacrifices, you become a more disciplined real estate investor. 

Our strategy involves being disciplined and content to hit a lot of singles. 

Yes, you can take out a 30 year amortization and pay it off in 15 years IF you are disciplined enough.

Ironically, our inability to compete in bubble market lead to us become more far more disciplined savers. 

If you aren't disciplined enough or make a good amount of many, like many, you may only make the minimum monthly payments.