as you ask about
sculpting barrels, i guess an easy way would be as follows:
roll a rough barrel shape from cheap putty and allow to dry (or use a piece of plastic tubing).
once dry, cover with a sheet of green stuff.
cut long vertical lines to outline the planks of wood.
gently press shallower lines along the length of these planks for a grain effect.
once dry roll two lengths of putty, wrapping one around the barrel just short of the top and one just short of the bottom.
texture again, marking a vertical line halfway round (illustrating where the bent plank has joined).
place flat discs of putty on the top/bottom for lid/bottom and texture with planks and grain as the main body.
you could always use a needle to press dots where nails may be needed.
hope that helps
