When coaching children, there is no set way to develop players. If I found that perfect recipe, I'd bottle it up and sell it for millions. But while there are plenty of coaches on the search for the 'Holy Grail of Player Development', there is a simple truth that often gets overlooked. These are children, and they should be treated as such.
There are a myriad of factors that need to be considered when coaching children. Here are just a few to consider:
The size of the ball, the size of the field, the size of the goal. It all matters when you're eight years old. Playing with a size 3 compared to a size 5 can make the world of difference to a player's ability to perform simple skills/techniques. At such a young age, it's important to be on the ball as much as possible, getting as many touches as you can. Maybe try a futsal for dribbling topics (more touches required as the ball is heavier).
A large field might be good to give players more space and time on the ball but also consider how large distances are harder to cover for young players. The ball may go out more often on a smaller field but it might be more appropriate in terms of energy expended on such large distances.
And just to highlight the point about the size of the goals:
Young players go through a series of developmental stages at different rates. As a coach, it's important to be aware of these and how you can adapt sessions to accommodate players in these stages. For example, a five year old has two speeds, full speed and stop. Game's can be kept short with little breaks in between to accommodate their quick fatigue and quick recovery.
As players age, mature and progress to the next developmental stage some aren't ready to share yet. Therefore, using activities that are one ball per player allow everyone to get practice in and there's less arguing over who's got "my" ball. Typically, players at this stage can only focus on one task at a time; meaning decision making tasks are very difficult. This means less emphasis on tactics and more focus on technique and some problem solving.
Understanding what motivates an eight year old and why they're at practice can also give coaches an insight into how to structure practice and what the learning outcomes might be. Not everyone wants to be the next Messi and the role of the coach can be different from one team to the next. One philosophy I've worked under is to 'provide a fun and challenging environment giving players the opportunity to learn'. The emphasis is on the opportunity. Some players are there to make friends and belong, others are there just to have fun. Coaches should always give players the chance to improve, but should also be aware that an eight year old might have a different reason for being there. Some young players want a friend, some a mentor, others a motivator. It's the coaches role to wear each hat and cater to their players.
Check out Nick Levett's article; Children and some reasons behind ‘Play’: here.