Is it right to constantly advise and criticise children and other members in your family ?

I think that constantly criticising children and family members will not bring any positive results. This approach will discourage them and if the criticising continues, then in the future they we will become victims of inferiority complex. Advising your children and family members in a positive way is fine and before giving an advice always think twice whether the advice you are going to give will be used in a positive or negative way. If you have never listened to the advice of others, then you have no right to advise anybody.

Children need more frequent advice and even reprimand but this should not be constant. Let them learn from their own mistakes. Everyone learns from own mistakes. The elders and equals need be advised when they seek. Even children need be less frequently interfered with when they grow up as young adults.

Occasionally only and that too only when really needed, only then should one criticise or advise others, we need to be especially careful with the children because unnecessarily giving them frequent advises or criticise them all the time can play a havoc with their confidence, which at this age is quite fragile. So we should resort to other means such as gentle reminders or using sentences that begun with "i would very much like it if you.....' etc.

No surely not. If we do that constantly then they will feel little discomfort and demoralize.. We should give them advice but we can't make anything over.

Such children become kind of bullies in their future life who never find life easy and normal. It is not suggested to treat children in a critics way but we should give them a reason if they are found wanting.

Self esteem takes a big blow if the children are subjected to constant criticism, comparison with other children and ridiculing. It's during the formative years of a child the seeds of self esteem are to be sown by the parents.
Instead of ever lecturing to the children about the Dos and Don'ts, setting an example by the parents will go a long way. After all no educational institution is better than a home and no teacher is a better than parents.

It is always good to encourage the members of the family to be the best versions of themselves. This should however not end up hurting anybody as it does make them feel less confident.