Adhere to the old adage of "climb high and sleep low."
The one caveat I would add to that quote is to remember that "high" and "low" are relative concepts. While this practice is generally in place for extremely high altitude climbs, remember that the interval between "high" and "low" is often only around 2000 feet. If you are attempting 14K', sleeping at 4K' the night before is not the wisest move. Most people should sleep as high as their body can tolerate to get a reasonably sound night's sleep, while allowing acclimation to continue.
