Well shot glasses should be ok if your having them upside down to prevent moisture loss. My seeds took 3 days in soil and one in the towel so yea. Most people switch to flowering once the 'branches' start alternating but you can wait till it grows higher. Usually the flowering makes it grow half of wat it already is. So if your plant is 2 feet when u switch to 12/12 it should grow another foot or so.