Making a three year old a Link costume is gonn'a be REALLY easy. it's basically a large shirt and a cone shape hat, with a basic brown belt. Best bet would be to look at a t-shirt you bought him, outline it on your fabric, then extend the bottom edge about three to four inches, enough that it comes to mid thigh, there's your tunic. =D
Cosplays in Progress
The 13th Doctor - Doctor Who 95%
Still need to get - Couple clothing items...and a Paralyzer Blaster.
Mystery Cosplay - ???
Things to do - Armor...lots of armor and makeup.
"Look to the Skies...and the Hero will come..."