Have a look at other plants growing in pots and select which plants you are going to grow. This will influence the size of pot and its decorative colour scheme.
Terracotta or plastic pots
A selection of recycled containers such as metal cans or buckets if you wish to use them
PVA glue, paint, old gardening magazines, twine, paint brushes or marker pens
If using mosaics - pebbles or tiles and adhesive