How do you clone weed plants?

so ive tried twice now this summer to clone weed plants the first time i uses rooting hormone and left them for 2 weeks under a small light in water and they slowly died...now i am tryin a second time and i bought Super Phosphate and now they have been sitting for 2 weeks in a box with no light but it has water in the bottom and each clone is in a pot of dirt mixed with the phosphate and they look like ****!! what am i doing wrong!!!