A quiet room with not much in it to distract the mind is ideal; a setting with light and space has a brightening and clearing effect, while a cluttered and gloomy room has just the opposite. Timing 
is also important, particularly as most people’s days are quite structured with routines. It is not especially productive to meditate when you have something else to do, or when you’re pressed for time. It's better to set aside a period-say, in the early morning or in the evening after work- when you can really give your full attention to the practice. Begin with fifteen minutes or so. Practice sincerely with the limitations of time and available energy, and avoid becoming mechanical about the routine. Meditation practice, supported by genuine willingness to investigate and make peace with oneself, will develop naturally in terms of duration and skill.