How to make set curd at home?

Set cud can be made at home easily. Take milk (boiled and cooled) in a pot, add a tea spoon of curd into it and stir well. Keep it aside for 8-12 hours. Set curd is ready.
There are many reasons for curd becoming watery, not set and smelly.
Tips: 

• Always add curd into the milk. Not milk to the curd.
• The milk should not be watery.
• The pot should be clean and fresh. Don't reuse the pot without washing.
• The pot can be covered with a sweater or blanket type cloth in winter season for easy fermentation.