I use IAGirl's gelatin pt, and it's done well for me. Cheap, easy, and customizable. The recipe is now off-site on Pedaheh's blog
, and the thread about it on Curltalk is here
. After you pt, if your hair feels dry, be sure to moisturize afterward. Not very dry and a protein free rinse out conditioner may work fine, more dry and you may need a deep moisture treatment.