No paintover this time, sorry, but I wanted to note something about your colours. You seem to be using black for shadows. This is VERY VERY common, but it also tends to render things to be flatter or more cartoony than the artist was usually intending. Except in very harsh or extreme lighting, you will rarely find such black shadows. Another CA user (sorry, wish I could recall the name) described shadow as liquid that form disappears into, and I find that very apt. Most of the shadows you would be dealing with would have a shallow depth, and thus the shadow wouldn't obliterate the form. You'll want to experiments with slightly darker browns and maybe some hints of purple or blue. If the lighting is warm (and it looks to be) you'll want to keep these cooler shades to a minimum and concentrate on warmer shadows. Also a brown coat will have warmer shadows than a blue-grey coat. Lighting is similar. It's important to note that lighting affects how we perceive texture. On the coat, you'll want looser, broader, very subtle highlights if it is a canvas or cloth coat; sharper tighter highlights if it is leather, but back to broader more diffuse highlights if the leather is dusty. Metal has very tight highlights, often with only a sharp smooth transition between light and dark. Metal will also have brighter highlights than cloth.
Stuff you can ignore but might find useful, since it's more about technique and less about your pic in particular.
Now some folks are just plain virtuosos painting with broad strokes and evoking shapes, but sometimes it helps to practise with the smaller shapes first. (The following advice will work best in photoshop, although other programs supporting multiple layers and locked layer transparency will work.) So what I would recommend is taking your sketch and putting it on a layer that is transparent (or set to multiply) and then making individual layers for the major shapes and painting a flat base colour. This is the colour you see your object as being. Paint to the edges of the object in the sketch, and then once you are satisfied that you have covered the object with the base layer, lock your transparency. (In photoshop, this is the first little grid icon on the layers palette. If it is locked, a white square will appear around the grid icon when the layer is highlighted.)
Once you have your locked layer, then you can experiment with all kinds of broad strokes without worrying about the rest of your work. If you want to experiment with a new shadow over the coat, say, but don't want to mess up your current coat layer, you can make a new layer, and control click the original coat layer in the palette. Control clicking a layer selects the non-transparent sections of the layer. Then you go back to your new layer, paint the shadow on, fiddle with transparency, mask around things, whatever. If you decide you don't like it, well, you weren't painting on the original painted flats, but a layer above, and you can scrap that and start again.
one way to paint bolder is to paint light. give your work more dramatic lighting
and then with one stroke you can define a shape
look at baroque art I just googled it and right away you will see what I mean
I just wanted to add my advice: if you really want to paint with big brushes do NOT smudge.
Really you can do that later, if needed but I think you should first lower down your size bit by bit, use the alt-key (I couldn´t live without it) to blend (just where it´s needed at first and not everywhere) and pick up colors (but keep in mind that this method lowers the saturation). Smudging will destroy the edges too early in the process in my expierience.