On 02/06/2019 18:52, Jim GM4DHJ ... wrote:
should they be neatly filled or does it not matter? ....



Depends where you are putting them. I usually put even stones all around
the edges and fill in the middle with whatever's left over. What's more
important from a strength and stability point of view, is that you put
tie wires from back to front and end to end.

How many of those you need is obviously dependent on the size of the
baskets you are using. I can give you more detailed intructions if you
need them.