Our church provides white robes for all the children to wear (boys and girls). They can wear whatever they want underneath, but this way everyone looks the same. We have many low-income families in our area who couldn't afford a special dress or suit, so I believe that was their reasoning. I wasn't crazy about it at first, but it was nice that no child felt that he/she didn't look special.
They also fully involve the parents in preparing the children for First Communion. There are 6 Sunday morning sessions where the parents and children have classes together and work on a workbook, discuss it and work on a project together. Then the children are taken to another room to learn songs for the service while the parents plan decorations for the church (altar cloth, pew banner for each family, etc.). I really loved being a part of this process.
My oldest is being confirmed this year and I've been very impressed with the preparation for that also. Their community service project for this class was to prepare and participate in a Youth Mass. It's really drawn the kids together and provided a Mass geared towards teens, held on Sunday evening.