Everyone has inherrant healing abilities; we can all channel unconditional love, which is a healing energy in and of itself. When we give healing from ourselves, we can become drained. One of the benefits of a Reiki attunement is that we no longer drain ourselves, as we are giving Reiki energy, not our own. The attunement process tunes you into Reiki energy, not unlike a radio tuning into a specific station. As part of the attunement process, the Reiki master-teacher will place symbols in your energetic field (aura). These can be thought of as energetic tattoos: Reiki is for life.
Traditionally, a student would shadow their Reiki master-teacher for at least a year before their 1st degree attunement. They would continue shadowing their Reiki master-teacher for at least a year between attunements. Students were only offered a 3rd degree (masters) attunement if and when their master-teacher felt they were ready.
You do not need to have all three Reiki attunements in order to channel Reiki healing. 1st degree is all you need to give healing to yourself, friends, family, plants and animals. Reiki students wishing to go in to service need to go onto 2nd degree. Those wishing to go on to teach and attune others need to progress through 3rd degree to master-teacher level.
The 3rd degree attunement alone, is not adequate training to become an effective Reiki teacher. Traditionally, this degree was divided in to two parts. As a Reiki master-teacher you will need effective skills in communication and groupwork; you´ll need the ability to ´read´ people, both psychically and through body language; you´ll need teaching aids, such as manuals, cd´s etc.