This is a very general guide showcasing a few basic tips and techniques to give a relaxing massage. If you are interested in anything further, please seek out an accredited school for massage therapy. There are good schools in most areas that will be more than happy to have another student.
We will be covering a few topics that can change the entire face of the massage and will have an impact on the end effect. First is positioning of the recipient. This includes the environment. A quick chair massage on the corner of a busy street will have a different feel from an hour session in a darkened, quiet room. We will concentrate on the latter, as they tend to be both more relaxing and a bit more sensual. This is an erotica site, after all. The most relaxing environment for most people is actually fairly similar to what most consider to be romantic—a room with the harsh light blocked, perhaps with a low wattage lamp or a few candles burning, or with window shades and curtains drawn to mute the light of the outdoors. Temperature should be set at a level that's comfortable for a naked person without being too warm for you. It's very possible to literally work up a sweat if the temperature is just a degree or two too warm. Soft, soothing music or nature sounds can add to the overall effect. Another option is to set up outdoors, preferably in a screened area. A sudden mosquito attack has ruined more than one good massage.
It's also important to have a good working surface. This should be stable and hard enough to hold up to quite a bit of pressure without breaking, yet soft enough to be comfortable for the person being worked. My personal table has been tested for over 500 pounds of working pressure. Even weighing just over 100 pounds, I have been known to put nearly 300 pounds of pressure on a person. This in addition to their weight adds up quickly. Whatever surface you use should be sturdy enough to handle this. It should also be at a comfortable height. A good height for most people is at about crotch level. When the client lays down at that height, your hands will generally rest at just under waist level. Something in that general area will allow you to put downward pressure on a person fairly easily without having to bend and strain your back. The working surface should be covered. If your room is a bit cool, an electric blanket on a low setting covered by a sheet is a nice touch. Your client would lay on top of that, then be covered by another sheet and possibly a light blanket.
Once your area is set up, positioning your client is fairly simple. They should be between the layers of sheets and laying in a way that is comfortable to them. If on their stomach, it can be useful to tuck a pillow under their ankles. This provides support for the ankle joints, and will put less strain on them while you work on their calves and hamstrings. If on their back, tuck the pillow under their knees. This will keep strain off of their lower back, hips, and knees. They should be under at least one sheet, possibly more if the room is cool. It's better to have the inconvenience of having to fold back a sheet to keep them comfortable and warm than to have them chilly and unhappy.
Also take into consideration what type of lubricant would be best. There may be a reaction to certain types. For example, if the person you're working on is allergic to nuts, it would be best to avoid almond oil and lotions that contain nut bits. If they are prone to acne (or backne) it's better to use something a little less greasy and no oils whatsoever. I personally prefer to use either pure jojoba oil or a crème made by Massage FX. Both have a pleasant scent, and neither have caused any sort of reaction so far. No matter what kind of lubrication you decide upon, please remember that you are not greasing a pig. Use it sparingly. Enough oil or lotion to make your hands glide smoothly feels good. Swimming in puddles of the stuff does not. It's easier to add than it is to take away.
It feels better to the person you're working on if the oil is heated slightly before touching their body. A simple but effective approach is to squirt a small amount into your palm, then rub your hands together. It serves a dual purpose—to heat the oil and to lubricate your hands. This is important, as most of relaxation massage is a gliding stroke, not a rough pounding (tapotement) or kneading (petrissage). It's difficult for your hands to glide smoothly over the skin without proper lubrication, and the rough feel can be less than pleasant.