A lot gets put on the priest. Do seminaries prepare him for this role? Do bishops emphasize this in continuing education with their clergy? Consider that the exodus of many Catholic children begins at the end of their grade school years, even after they enroll in Catholic high schools and universities, clergy should probably consider the message they send before this exodus, don’t you think?
23. It is the responsibility of the priest who celebrates with children to make the celebration festive, familial, and meditative. [See DMC 37.] Even more than in Masses with adults, the priest is the one to create this kind of attitude, which depends on his personal preparation and his manner of acting and speaking with others.
All too often, the childish intrudes on a priest’s style–too many adults, really–when speaking to children.
The priest should be concerned above all about the dignity, clarity, and simplicity of his actions and gestures. In speaking to the children he should express himself so that he will be easily understood, while avoiding any childish style of speech.
The free use of introductory comments [See GIRM 11.] will lead children to a genuine liturgical participation, but these should be more than mere explanatory remarks.
Say more that what’s just in the black:
It will help him to reach the hearts of the children if the priest sometimes expresses the invitation in his own words, for example, at the penitential rite, the prayer over the gifts, the Lord’s Prayer, the sign of peace, and communion.
Thoughts on this?
Catholic Sensibility 
The difficult thing is to not patronize children with what we adults would think appeals to them. What’s difficult about it is that children are as varied in adults in their tastes, and what appeals subjectively to a plurality of children might really turn off a no-so-small minority of others (you may tell I was in often in one of those minorities). So understanding how deep appeal vs. its opposite may run is important. And it’s more of a gift than a skill, though one can be trained out of more ham-fisted ignorance of signs to look for.
First and foremost: do NOT try to be cool or slum, as it were (that’s another way of saying what the instruction provides). You cannot be cool, even if an occasional child condescends (yes, children can condescend just like adults) to flatter you into thinking you are. So don’t even try. Don’t give the slightest impression that you are deluded that you can.
By the same token: don’t try to make Jesus cool. Jesus is beyond cool. Kids need to find someone who is beyond cool – they are already mired in coolness.
Another: be on the lookout for the kids who are being left out by the others. While that’s primarily a job for parents and teachers, since you partake of both of those roles in a way, it’s also yours – and if you fail at it, those kids may learn that God does not really mean to include them – a life lesson that the most gifted of them may never unlearn. Don’t make pets of them (that may well worsen things) or patronize them. But avoid making connectedness the be-all-and-end-all of the Social Gospel – because these kids often find that an insurmountable hurdle. The neighbor for them is not necessarily someone they can trust, and these kids need to know it’s sometimes OK as Christians not to trust (hmm, might we see other applications of this???). So you may have to do some seriously sophisticated preaching about the Golden Rule and related commandments of Jesus. Because gifted victims often learn spiritual lessons out of season that they really should learn later in life, and it’s harder for them to unlearn them. I envy no priest in managing that one.
I agree
I’ll answer after I eat my curry