Ride confidently and position yourself where you are most visible.
Riding behind your children
Riding behind your children will often be the most practical option. Ride behind and slightly to the right, where you can see your children and ride at their pace. This will create more space between them and the passing traffic. Ensure that you are close enough to hear each other. Encourage your children to check behind regularly to check you are still close.
Riding as a group
It is a good idea to position the children who are most proficient at cycling (e.g. trained to Bikeability Level 2) at the front. If there are two adults in the group then the best option is to have one adult in front and one at the back. If there is only one adult, make a considered decision about whether it is safe enough to have more than two children in the group.
Riding side by side
You may ride side by side with your children, positioning yourself on their right. (The Highway Code advises you not to ride more than two abreast.)