Later you apply a layer of lime earth or acidic sand, depending on the type. To prevent erosion, add plenty of grass seeds from an orchid meadow to the upper layer. If the biotope is not too big you can water it profusely and perhaps cover it with a transparent foil until the seeds have germinated. In this stage you can make minor corrections before you apply the companion plants.
When the grass has germinated and the ground is stable enough, you can apply roots and bulbs of plants which can grow together with orchids, like Iris or Pulsatilla. Watching the natural plant sociologies can help. KNOW THE ORIGINS OF YOUR SEEDS AND PLANTS, this is a general rule, and GET THE NEEDED PAPERS FOR PROTECTED PLANTS. It would be a pity if a mindless paragraph-rider destroys the work of several years, I know this, believe me!
Finally, you can apply orchid bulbs and seeds. Mild watering in the initial adaption period may be a good idea, if possible.