A guru will usually make new disciples follow this dakshina marga and there are many well-known stories that illustrate the arduous life that a disciple must pass through. Those people who have read the biography of Milarepa will remember how his guru Marpa made him work day and night on many projects. His guru made him build houses and then destroy them when they were completed. Milarepa almost despaired. For many years Marpa refused to teach any of the traditional teachings and practices which Milarepa so ardently desired. Instead he made Milarepa work and work on so many seemingly useless projects. This is an extreme example of the right hand path.
There are also many Zen and Tao stories which illustrate this same path. For example, an aspirant goes to a sage and asks for instructions, initiation or whatever. For many years the sage makes the disciple clean the floors, work in the kitchen and many other tasks. Possibly, the sage does not teach the disciple even one conventional spiritual practice or give even one concrete, recognizable instruction. All the disciple does is work, work and work. This is the right hand path. It is the stage where the disciple removes his most obvious blocks. And what is most important during this period, awareness (the sushumna) starts to spontaneously awaken.
When an aspirant is sufficiently harmonized, then he can start to tread the vama marga the left hand path. Actually a better name for the left hand path is the vipareeta marga (the reversed path) or the nivritti marga (the path of ascent or return to the source). This indicates the stage in spiritual life where one is ready to awaken the inner awareness of the mind to a greater extent. Here the ida is given more emphasis, but one still follows the pingala path, the path of action. One starts to make greater progress in expanding inner awareness (ida) but while simultaneously balancing this with karma yoga (pingala). The left hand path of tantra consists of three acharas or stages and are generally associated with a guru-disciple relationship. It is this vama marga that leads eventually to higher understanding and realization of one’s fullest potential. It is this path that eventually leads to that which is beyond both the ida and pingala – the sushumna flow to sahasrara.
Here in tantra you will see that the balance of ida and pingala is implied. This applies throughout all the stages, from the progressive transition from the right hand path to the left hand path. The system of tantra is really a science. It is exact in its methods and sure of its aim. It has been tested and developed over the last few thousands of years by countless sages. It is for this reason that it brings results.