The lilies of the field are the wildflowers we see every spring - the wildflowers of the Bible were probably anemones. Tissue paper works best. Use eight sheets of any color. More than eight sheets becomes too thick to cut after the paper is folded, but eight sheets give a very rich, full flower.
Any size works well.
For each flower, cut eight squares of tissue paper and stack. Fold the stack once on the horizontal, once on the vertical, and once on each diagonal. Bring the opposite folds to meet in the middle. Cut a curve at the top of the flower. For very small children, I do all the preparation up to this point.