I would take 1 soma (350 mg) with your normal dose, that's usually what I do. I wouldn't do more than that especially your first time. Soma is definitely one of my favorite potentiators, its pretty dependable. The thing you should remember about potentiators is not to over do it. You don't need much to get the effect, if you use too much it will overtake the opiate effect and sort of ruin it.