I found the original idea here: but it’s in French and doesn’t seem to specify the size of sock to use.  You could also trim the edges of the legs with lace or ribbon for something fancier.

I hope that the picture is large enough.  The doll I made it for is one of the Hearts for Hearts Girls.  The original site was made for the Les Cheries.  I imagine that the pattern would fit other 14 inch dolls too.  Larger socks might be usable for 18 inch dolls or even Cabbage Patch type dolls.

I’m posting (re-posting) this mostly because doll clothes for this size is hard to find.  Both the Paola Reina and Les Cheries are from Europe (Spain and France, respectively) so the patterns and tutorials are usually in Spanish or French.