Prepare a makeshift furnace from a charcoal barbecue grill. This method uses the heat generated by a large charcoal fire to melt silica sand into glass. The materials used are relatively cheap and common - theoretically, all you'll need is a short trip to the hardware store to be ready to make your own glass. Use a large charcoal barbecue grill - standard-size "dome" models work well. Use the thickest, sturdiest grill available. Most charcoal grills will have a vent on the bottom - open this vent.
Even at the extremely hot temperatures reached in this method, it can be difficult to melt silica sand in a grill. Add a small quantity (about 1/3 to 1/4 of your sand's volume) of laundry soda, lime, and/or borax to your sand before you begin. These additives lower the sand's melting temperature.
If you're going to blow your glass, have a long, hollow, metal tube handy. If you're going to pour it into a mold, prepare your mold beforehand. You want a mold that won't burn or melt from the heat of molten glass - graphite works well.