Silver Fox's post today reminded me of a common problem I would run into when sampling: unlikely "stratigraphy". In her case, her samples got mingled together.
I quickly figured out that if I had the same soil type in the first couple inches of the sampler (every 2 feet, natch), then I was getting some "slough" in the top of the sampler. There are ways to minimize this - a common and easy way is to only collect 1 sample per interval and not "stack" the samplers. The problem is always convincing the driller that we need to use the slower, more tedious method.
One of my earlier posts complained about my problems convincing drillers to do what I needed. At this point, I think I've been able to overcome my short stature and youthful looks - the key is to be friendly but firm in the beginning...and find a way to work my actual age/experience into the conversation as soon as possible.