This is how St. Cyril of Jerusalem instructed the newly-baptized in his congregation during his Easter sermon in the year 348:  “When you approach Holy Communion, make the left hand into a throne for the right, which will receive the King.  With your hand hollowed, receive the Body of Christ and answer ‘Amen’.  Then consume it, taking care not to lose any of it.” 

There is no “absolute” way of taking Communion.  However, the following steps might be helpful, always remembering that the first rule is reverence.

1.  Place one open palm on top of the other.  (If you are right-handed, the right hand should be on the bottom; if left-handed, the left hand should be on the bottom.)
2.  The minister says “Body of Christ”, you reply “Amen”.  Bow your head slightly.  The minister places the Host in your open palm.
3.  Step aside to make room for the next communicant.
4.  With your lower hand, take the Host and place it in your mouth.  Only after this, return to your place.