Wait until the stem is dry and turns brown.Cut them off the vine leaving as much of the stem as possible.You can place them in a dry,well ventilated place to dry.Sit them up off the ground on something where they will get air circulation all around,like a palet or something similar.I slipped some down into the legs of old panty hose and hung them in the rafters on my deck last year and they dried very nicely.Don't dry them in the house.The mold is bad for you.People have different methods of drying but I had good success with the panty hose method.It will take several months for them to dry depending on size,climate and such.When they are hard and the seeds rattle when shaken they are dry.Have fun,they are addictive!......Lillie