You don't have to be very smart to prepare an OIC because the people who review them at IRS are not very smart either.  They just follow instructions.  How much can the taxpayer raise by selling assets or closing bank accounts?  And how much can the taxpayer pay with expected income and allowable (not actual) expenses?  Just fill out forms, like everything else involved with tax work.  You can usually rule out any chance of acceptance, with some preliminary work.  If it still looks viable, do it yourself as a learning experience or farm it out to someone who practices mostly in collection work.  If you're in (or near) California, I can suggest someone.