Not really that hard, just time consuming with all the masking.

Start with the lightest color and build up to the darkest color, masking off your splinter pattern along the way.

Don't be afraid to overlap the masking of the 2nd and 3rd (and 4th if you are going that far) colors over the previous colors, adds a bit of intrigue to the camo.

Not sure what you are doing it on, but here are a few examples.

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