Steps to make Potting Mix :
Take cocopeat block and put in a tub. Add around 6.5-7 litres of water to expand the cocopeat. Don't add water in one go. Add around 80% of water and the remaining as per your requirement. Break the block with your hands and let it expand completely.
After a few minutes once cocopeat has expanded completely, add the remaining items - Vermiculite, Organic Fertilizer and Neem Powder and mix them completely.
Fill up your grow bags or pots with this potting mixture. This mix can be used for all vegetables, fruits, flowers, indoor plants etc. If you want to store the unutilized potting mixture you can keep it in any container, just ensure it is moist so that the microbial activity is alive. You can keep adding little water every few days to keep it moist.