How to promote cognitive development at early age?

Cognitive development consist from:

• Imagination
• Creativity
• Memory skills 
• Concentration skills
• Problem-solving skills
• Concept formation

Imagination is the ability to form mental images of objects or concepts that are not present or that do not exist yet. Imagination forms the basis of many of the activities that humans find enjoyable, like reading books or dance. Creativity is the expression of imaginative ideas in a unique way. Creativity can be expressed in many different ways, like artwork, photography or gardening. Memory skills is vital part of learning and therefore cognitive development. Memory involves three tasks: encoding, storage and retrieval. Concentration skills is focusing or pay attention on a task. Problem solving skills is the ability to figure out and solve problems. First children just try and experience, but later, children are able to mentally predict what will happen, before they try anything out. Concept formation is the ability to create mental pictures about the world, and helps us organize and make sense of the world around us.

There are many ways cognitive development can be promoted. 

• Talk and interact with a baby from birth.
• Provide plenty of interesting activities for the child, like painting, play dough, water pool, small world toys, puzzles and construction toys.
• Allow children to explore the world around him/her. Visit the park, go to the nature.
• Provide plenty reading/writing materials for children. Read with and for children and ask them their opinions on what they have read.
• Have children help out with household tasks in meaningful way - baking, gardening, etc.

Some games an toys will help you to promote intellectual development. 

Chess for example is a great fun but meantime it teaches children strategic thinking and logic.  So when you buy a toy select them carefully and buy a "Learning Toy".