The very best seller financing term is a Commercial Master Lease. You can discover how to do this in the Commercial Funding Secrets Course. You'll also want to go thru the Instant Offer System Training to learn Peter's 5 Steps to getting sellers to say yes to your creative offers.
If you are negotiating owner carry financing, make sure to get as low as possible interest rate and as long a term as possible. Peter shows you how to do this in the Instant Offer System Training.
If you can't get a low interest rate, then try getting a graduated interest rate that starts out low and goes up over time. Like this:
Year 1 - 2%
Year 2 - 3%
Year 3 - 4% Year 4 - 5%
Year 5 - 7% Year 6 - 10%
This helps the seller to feel better and from your end, make sure to sell or refi the property before the interest rate gets too high.