
Children start by copying scribbles. They will then move on to trying to copy a line they have seen drawn. By the age of about 18 months most will be able to scribble spontaneously.
At age 2 a child may be able to copy a vertical [up/down] line before being able to copy a horizontal [side to side] line which will be managed around the age of 2 and a half. By age 3 a circle can be copied with some skill.
Around the age of 3 and a half a child will try to copy a square that
they have seen being drawn. They will also trace around the outline
of pre-drawn diamond shape, however the corners of the shape will more
than likely be rounded.

Copying a cross [+] is generally possible at around 4 years and they will also trace along the outline of a square and a triangle although they are unlikely to be able to draw them with skill. Before age 5 however they generally manage to copy a drawn square and may trace round the drawn shape of a diamond.

By the end of year one at school children become more skilled and
more confident. They will copy a drawn triangle shape and may now manage
to copy a diamond shape with some skill.
When a child first starts to reach out for and enjoy using crayons
they will generally use either hand, often swapping from one to another.
As they become more skilled and begin copying shapes most will begin
to show a right or left handed preference. For a child to develop their
pencil skills it is important that the child is able to make this preference
clear for themselves and then be encouraged to draw with that hand
using their other hand to hold the paper steady. Continuing to swap
their pencil from hand to hand after a child has started to show some
skill in tracing shapes will make it harder for them to learn the control
they will need for letter formation at a later date.
Reproduced with kind permission by Jill Steward, Occupational Therapist, Surestart, Stoke North.