Q: How to change a child's whining habit?

It's universal! Kids whine at so many things. It would be tough to recommend a solution without knowing the context. Why do they whine, when do they whine (are they tired?), what do they whine at? It is also important to understand your parenting style. Are you patient, or a disciplinarian, a firm parent or an easy going one?

At its heart whining is a reaction to something that displeases them. I would recommend to take some time to evaluate whether the concern is valid even if you feel a strong urge to shut down the little whining machine for some peace and quiet.

A quick list that I would look out for:
        1. Are they in any physical discomfort e.g. Have they had enough rest, are they hungry, cold, tired etc. Sometimes they whine about the smallest things if they are feeling a general discomfort.
        2. Is this a common, recurring issue? Eg. Whining related to sibling rivalry? These may be big issues that require its own toolkit altogether.
        3. Is this ‘trivial’ whining because they do not get what they want. Even this is debatable. We may think that adults know best, however in some areas, it may be worthwhile to allow the child some flexibility to decide for him/herself.

There is no one quick solution to solve this, rather a trial and error approach is required as with most parenting issues. One or a combination of the following may work:
        1. Encourage mindfulness in your child. Regardless of the reason, you can encourage your child to breathe in and out slowly when they get angry. This is a habit you can ask them to practice when they are not as worked up. Is this useful? I've tried on my daughter and this has calmed her down somewhat enough to be able to negotiate with her or work out alternatives.
        2. There are thoughts that letting your child have plenty of outdoor opportunities will allow them to expand their energy and hence reduce whining due to boredom and need for attention. I noticed that they are generally happier and in a better mood with physical activity. But still quick to whine if they don't get their way.
       3. Listen, empathize with their concerns and offer alternatives if you cannot go with what they want. This, is for the patient, nurturing parent that we all aspire to, but often fall short of. Try this if you are in a good mood and then take time to feel amaze that sometimes listening to your child works. But often we are the harried, multitasking parent, probably with one eye and ear on another sibling or on the phone. This may not work too well and may backfire as you get no results from your half hearted efforts. As pragmatic parents, don't worry about this and move on to other approaches.
      4. A firm stance with a touch of humor may do it. Eg. You want your child to stop watching the TV and she whines about it, be firm that no TV after a certain time is allowed. But you can diffuse the tension by making silly faces about how tired she would be or proposing a pillow fight etc. I'm not the silliest person around. But it works for my husband who uses this to great effect. Being irreverent works but only for trivial matters.

The larger picture, would be to have kids that are able to problem solve and deal with disappointment and issues that crop up. Building kids resilience and values is a journey that hopefully plenty of coffee, diy facials and chocolates will give you the patience and endurance to see through.