For the begining meditate on each one in order for 1 minute each, total 15 minutes, 3 days in a row.
This is from my point of view to integrate the energies and to help feel the energies.
After this period you can use them as you feel you need them. For example: meditate 1 minute /3 symbols a day/ only one symbol a day ( choosing the ones you feel you need to/ purifying a room by letting some of them or all radiate in that room (drawed on a paper or lcd).
Use your intuition to use the ones you need and when you feel to.