paying off the mortgage- the best strategies?

[Account Closed]

Ok so I would like expert opinions on the best mortgage options for rental/income producing properties. If I have a positive cash flow prop, is it wise to apply the positive cash to the mortgage principal? does that help pay a 30 yr fixed down any faster or is it not really worth it and I should just pocket the leftovers? Im not an accountant and I hate math but RE is such a numbers game and Id just like to know the smartest ways to finance a rental portfolio. Also are 5/10yr interest only mortgages worth it if Im planning on selling a property only a few yrs after acquiring it for a nice return? do smart investors use int-only for short term investments?