I couldn't agree more with Jaime! Are you SURE this is your first time? :0
Two suggestions -
(1) deepen the folds of the bag next to the canteen and next to the figure. You could do this with just a surgical blade or there are also etching tools that work well. The effect will be to bring each of the items a bit away from the surface and give them a more realistic look.
(2) the figure will look more like it is carrying a bag with some weight if you cut off the top part of the bag strap, cut into the shoulder a little, then re-sculpt the strap in the crevice. Several people suggested that trick to me but I think John Long actually got the point across to me, so thought I'd pass it along.
Keep up the good work!
All the best,
Dan