Cut a strip of cardboard to whatever depth you would like. If you only have paper then fold it a few times to strengthen it as the flowers, leaves etc will get weighty. You could also use an old weetbix box, thicker paper from junk mail or last month's calendar page to make a crown. Size the crown to your little tots head and then staple the crown, cut the excess length off.
Gather any leaves, flowers, grass seed heads from your garden, local park or while out for a stroll. You will need to glue or staple the foraged pieces to the crown for your little tot. Start fixing the flowers, leaves, grass heads onto the cardboard crown to where your little tot would like them.
Once your little tot is happy with their crown they can wear it for the next day or two. To make it last longer store in the fridge.