This is a quick tutorial on how to achieve convincing battle damage that is quick to do. This walker is from the Mercenary faction from Dust Tactics. The model itself is a Russian walkers with German weapons. I've decided to paint it as an Allied vehicle. Total paint time was about three and half hours.
Here is the walker painted in an Olive Drab Modulation scheme. If you want to learn how to do that, I wrote a tutorial with the Gundam Zaku II.
The tools you will need are paint (AK Interactive Chipping Fluid or any Dark Brown Color), paper towel, an alligator clip, and a piece of sponge. I'm using a portion of blister foam from a metal model. You can also use the leftover sponge from your transport bags. I've also seen people get the same effect with a kitchen sponge although I have never tried. All there is to do is rip a small rounded piece of sponge and clamp it with an alligator clip. You can just use your hands here, but I find more control with the clip. Simple dip the sponge in the paint and dab it on the paper towel until the majority of the paint it off and each dab leaves an irregular pattern. You can experiment with how much paint you have on the sponge. Start with less.
Now dab the sponge onto the parts of the model that you want to be weathered. Focus on the areas that will receive the most damage. Edges, the feet, etc.
As you can see here, I've concentrated more damage on the feet of the walker. Start with small sections, you can always add more paint, but removing paint is difficult. If you do make a mistake, you can wipe away the paint with a wet Q-tip if you are fast enough.
On some models you may want to emphasize the chips like I did on my Zaku II. On the Zaku, I've hand painted a highlight on the bottom edge of the chip to give the effect of depth. This step is optional, it depends on how you want your model to look. Highlight the chips with the light color you used for your base color. If you didn't paint any modulation, mix your base color with a Buff or Ivory color. This technique takes a lot of patience. Remember to go slow, take your time, and use a very fine brush.
As you can see, I've opted not to highlight the Mercenary Walker. This chipping method is a quick way to add realistic weathering to your model.
And a back view. I know there is a gap between the barrels, but the Dust models come pre-assembled and I didn't want to waste time correcting the builder's mistakes. It may take some time to get used to this at first, but once you get the hang out it, you can weather a model in just a few minutes.