Alright well im back and need some advice...

I am going to make a box for the plants to grow in...I have a big cardboard box, i was thinking of lining it with tinfoil ect. and putting a light or two that will hang from the top. Is this a good or bad idea? Obviously its better than what i was doing before, but is there something i should know about this idea?

Also, i bought some miracle-gro all purpose plant food, and some miracle-gro moisture control potting mix. I was wondering what would be the best thing to do with the potting soil. Is it bad to try to mix the regular soil with the potting soil? How would i do this without ruining the roots and such? And should i feed the plants with nutes everytime i water? or every few days?

I know that some of these questions have been answered on other threads, but i get a lot of questionable answers, that seem to be right and wrong on different threads...what is your advice? Ill get a few pictures up when im done. Thanks.