I've always hung baskets of flowers from trees.  Not sure where this idea came from, maybe early Martha?  It really brightens up your yard.  I usually do petunias and these hot pink guys did great this year.  Usually in each basket is a 6-pack.  Consider the cost of reusing your baskets and just planting a sixer instead of purchasing new flower baskets every year.  Beautiful color at a fraction of the price!