Garam masala is a common mixture of spices used in Indian homes. The composition of garam masal varies from region to region of India. You can buy garam masala powder off the shelf in most Indian shops. To prepare your own garam masala powder, grind together 4 nos. cardamom, 1 no. cinnamon of 2 inch size, 2 nos. cloves, and 1 no. bay leaf (optional). If you want more of garam masala, increase the quantity of the ingredients keeping the proportion same.
Many of the Indian recipes are a little hot for the international palate, unless, of course, you are from Mexico. Use chili/ pepper using your judgement, irrespective of whatever is mentioned in the recipe.
Ghee is common ingredient for many Indian recipes. If you do not find ghee, you can use butter instead. However, in that case, I suggest you melt the butter, and heat it under a low flame for 5 mins, so that you get the aroma of ghee.
In any cooking where you need to add water, it is better to add hot water. It saves time and improves the taste.
There is a simple rule of thumb for controlling the consistency of gravy. Cook on high heat, and keep the cooking vessel uncovered to evaporate water to make the gravy thick. Cook on low heat, and cover the vessel to keep the water from evaporating and keep the gravy thin.
Another way of thickening gravy is to add a little flour to the gravy and stir.
For cooking roti over direct fire, wire pans suitable for holding the roti over fire is available in the market. An electrical heater by the name of 'Roti King' is also avilable in the market for the exclusive purpose of baking roti. If you can get hold of one, just put the flattened dough in the heater and press the lid tight, and heat it according to the instructions to get a perfect roti made without having to worry about the shape and fluffiness.