You are not going to be able to generate significant income on vanilla, long-term rentals without a significant amount of capital invested.  

Accessory Dwelling Units (ADUs) are an increasingly popular way to generate additional rental income on an existing property.

However, if you're a W2 high income earner or business owner, I can't imagine it makes any sense to flip houses, mail mass post cards, wholesale, or build lead gen websites with the value of your time being better spent other places (such as learning about real estate and increasing your income through proven means), such as at your 9-5pm or growing your business, and your real estate is a long term process and you don't need "home run" deals to qualify or make it work.

I bring to the table my full expertise in project management, construction, and deal sourcing, along with the knowledge I’ve gained working tirelessly in this industry over the past 3 years.My vision is to dedicate the next 10-15 years to real estate development, growing projects that generate significant returns while delivering exceptional results.If you’re interested in learning more, I’d love to discuss how we can collaborate.

. - if I use my cash, the investment needs to generate > 5%.

@Henry Perez  Things like websites, bios and marketing materials help on credibility as well as your LinkedIn and Facebook profiles. 

If it is a pet, be aware that they could get paperwork saying it is an emotional support animal (if so tell them it needs to be from a local medical professional not a website) or say that they don't have a pet.

Spent a minute on their website and this in particular stood out to me as a red flag.

Things can and will go bad, but once there is enough monthly cash flow generated it will be extremely difficult for that one big issue to put us away or even 2-3 big issues all at once. 

You can look on websites like https://www.corporatehousingbyowner.com/search/United-States... and https://www.furnishedfinder.com to see what similar houses are rented for.