Please see the attached word docs to assist in making your U6-U10 practice sessions. Don't forget that most times, simple activities are the best for the kids - most times they are more fun for the kids and they will get a great deal out of it skill wise.
Also, keep in mind that there are just some things that the players are not yet able to "get" yet- that has a lot to do with the variuos types/stages of development that all children go through while growing up. Sometimes the Psychosocial, Cognitive and/or Psychmotor development of the players may not be at a level where the players can actually do what you are attempting, the attached sheet gives some basic expectations for the U6 and U8 player. Keep in mind that not all players will be in the same place developmentally, as they all develop at their own rate.
U6-U8 Player Characteristics - Download Here