Honestly I have found it very difficult to find seller finance deals that make sense. So if you are finding them, kudos to you. I would think of them as any other lender. Make sure the deal stacks up when you compare it to a bank loan, agency, or any other loan opportunity. Don't do a seller financing loan just to do a seller financing loan. Make sure that the loan brings something to the table. Are you not required to personally guarantee the loan, when you typically would with a bank? Does it have better terms than you can otherwise get? Do you have flexibility to prepay if you choose to refi or sell? There needs to be some reason to do it. Because your counterparty is going to be Joe Schmo rather than a professional institution which will likely add some challenges that you're not used to. Also, I would suggest have legal counsel to make sure everything is documented correctly.
If you are negotiating a seller financed deal, I'm happy to run a few models for you to evaluate different proposals.