Sandra Dodd - unschooler/encourager/mine of information speaks of "Strewing The Path"
One valuable way of doing this is to be a little organised with equipment if you can.
This battered old school case (mine) from the 1970's (vintage!) holds a treasure trove.
I've collected bits and pieces, nothing flash, for cardmaking. Stickers, bits of coloured and patterned paper, pre-folded cards, bits of pictures the children have painted/coloured/drawn etc.
The easiest way for children to make cards, that I've found, are by using punches.
I try to make sure that we don't put rubbish back into the case.
If it's neatly presented even the most reluctant child can be drawn into the game.
One of my children, on feeling the desire to make cards, would happily go around the house collecting materials to make them. However, the others would go off the boil very quickly if they needed to hunt for stuff.
So this just one way we strew the path.