As I stated previously, ritual is not imperative to successful meditation. In fact, I discovered after a few months of practice, I was able to meditate in a crowded commuter train, although I do not recommend it. Being yanked out of a deep meditation by someone swaying against you is not really conducive to fruitful meditation. :-) With time and practice, I learned to achieve the meditative state at the count of three, which can be very useful.
If meditating simply for the mental and physical benefits of reducing stress and allowing the body to heal and attain balance, a quiet dimly lit room is all that is required. Pick a spot where you can sit comfortably and not be interrupted. The meditation process is the same. Sit comfortably, eyes closed, feet flat on the floor, hands resting in the lap and begin reciting the mantra you have chosen. Twenty minutes twice a day is best. When finished, sit quietly for a few moments before resuming your daily activities.
Sitting is best when learning to meditate. If you recline or lie down, sleep will often overtake you. Most people are sleep deprived to some degree. The body also needs sleep in order to heal or improve it's effectiveness. Falling asleep while meditating can be quite distressing to a person learning to meditate. If it does happen, do not be alarmed, or discouraged. Simply finish your meditation if you have time, or expect to stay awake next time. In meditation, we simply acknowledge whatever has caused our mind to wander, and then bring it back gently to the mantra. With practice, stilling the mind while awake and alert will become easier. You will still benefit from the practice even when the mind refuses to be stilled.
I prefer using a simple ritual as it helps to prepare the mind to be stilled and lets the mind know when the meditation is finished.