Children are mostly used to spoon-feeding and are not made a participant in household work. Therefore children do not learn to take responsibility for any work at home.
After a certain age when parents feel that children should begin helping at home, they may face agitation, resistance or anger among children on being asked to do so.
Children need encouragement and motivation to work. So begin with something that the child may find interesting. For example, children are active and like to be outdoors, so you can begin with asking them to help in the garden or lawn. They can pick up leaves, papers etc fallen on the ground or fetch buckets or water the garden.
Some children may like challenging work, while some may like monotonous work. Assign work accordingly. If the child finds the work boring, you may have to make it fun by either being with the child yourself, putting on music or rewarding the child with his/her favorite ice cream or chocolate.
You may also encourage the child in participating in work by assigning them the task of bringing things that they need. You can allow the child to buy items like biscuits, milk, toothpaste, pencils etc from the nearest store, and arrange the money to be paid yourself later on.
You may also have to stop pampering the children and letting them get away with their attitude of taking things for granted. Kids may throw around their towels, socks, handkerchiefs etc on the bed, chair etc. Do not pick those things for the child; tell them to put the things in the appropriate place. Remind the child that he/she has to clean up and you will not do it for them. Be serious about it.
Again, encourage children to themselves fetch their glass of water, milk etc, unless in situations where they are tired or exhausted after just coming back home. After they have finished drinking, tell them to put back the glass for washing in the sink and not keep it around for others to pick up.