Cover the seeds with a thin layer of worm castings or compost.
Gently mist with a spray bottle until the holes are filled with water.
Keep soil blocks moist by either misting with a spray bottle or soaking soil blocks in shallow water.
As the seedling grows, its roots will reinforce the soil block, holding it strongly together. When roots are visible on the sides of the blocks you can start to water with a seedling watering wand/can (rose pattern).
1.5 Inch Soil Blocks made with the 'Ladbrooke Mini 5'
Soil block seedling ready to plant, note healthy white roots