In article says...
Carefully select your seeds reading all of the information on the seed
packs. Pay attention to the height of the plants, and the time to
bloom, and the type of flowers.

So much carefulness - I guess that means letting them set seed
helter-skelter and thinning out the ones you don't want doesn't work?
That's my preferred method, seems to work pretty well
http://annzoid.com/Gardens/mutant.jpg

There are two types of gardeners, the laissez faire type who let nature
dictate the garden as much as possible and the controlling types who
want everything just so in spite of nature. Me, I take whatever
volunteers I get free and plant around them. I over seed planters and
let the strongest survive. Sometimes I do play God if the strongest are
being unfair to some of the weaker plants.

I have a neighbor who bought hundreds of pansies for his parkway and
planted them in all these perfectly straight rows. Every time I look at
that parkway I wonder if someone like him would have been a good Nazi.
:-)

Here's a pic of my volunteer sunflowers from last year. Unfortunately
for some reason I didn't get any volunteers this year. I think the
squirrels have been eating all the seeds.

http://www.brandylion.com/gallery/Garden_2006/IMG_3097