How to prepare the Garam Masala Powder?

Ingredients needed for the Garam Masala Powder
8-10  pieces  Cinnamon stick
1 tsp Green cardamom
3-4 black cardamom
1/2 cup Cumin seed
1/2 cup Black pepper corns 
1/2 cup Cloves
1/2 cup Coriander seeds

How to prepare the Garam Masala Powder?
Break the cinnamon sticks into smaller bits or just crush them a bit with a pestle.
Dry the ingredients in a microwave for a minute at high flame
Remove and then cool till they get to the room temperature.
Put them in a mixer grinder with a dry grind blade. Powder till they are fine.
Store in an airtight container. These might come to about 2 cups powder.

Points to Note:
After you microwave the ingredients , do see if they have dried / roasted properly. If they are not then heat it for a 30 seconds more.
Always see that the container you store garam masala powder is dry and airtight. Otherwise you will lose the flavour of the ingredients.
You can also add other ingredients like Khuskhus / poppy seeds, Saunf / Aniseeds, Shahjeera etc. But I have not added them as they will not get into all the recipes which need Garam masala. You can add the spices for making the powder as per your taste.