Glenda,
Eat the big ones. Plant the smallest. The bigger the sets, the more, and littler, will be the ones you harvest.
Actually, if you plant seeds, you will get the largest shallots when you harvest, however, I feel that seed planted shallots don't store well, at least here where its hot.

Coho:
Thanks for the info.Am I right with my thinking that you should plant the largest garlic clove to get the largest head? Also any tips for getting big cloves and heads? I planted gray shallots for the first time last year but the resulting cloves were pretty small. Thanks again.
Glenda

Do a search for garlic fertilizer. Perhaps one just garlic.There is a great deal of information.
There is a general feeling that you plant the biggest cloves from the biggest heads. you will do ok if you plant the biggest cloves from medium large heads. I have seen a comerical statement that you should plant only cloves from medium heads. I do both.
Lots of compost to loosen your soil unless you have Oregon sand. Then lots of compost to retain moisture and provide food for the garlic and shallots.
The only way to get bigger shallots is to plant smaller "sets" Even medium sets have many sprouts hidden in the sets. I am considering sprouting a few sets and then trying to divide them into singles and transplant. Kind of doubt it will work.