gathered front

[temptinglies.livejournal.com]

i think this is pretty easy so i'm not going to bother buying a pattern. how would i go about making a gathered front on a shirt (like this: http://www.mccallpattern.com/item/M4517.htm?tab=tops_vests&page=3)? in my costume class some people had to do those for leotards and i remember there being something with elastic. could anyone explain please?

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