Human food measurement

When it comes to cooking, I'm kind of fast and loose. I love recipes, but I tend to be a bit vague at implementing them. One reason for this is the units they use for doling out the ingredients. If you live in a sensible country, then everything is in grams or kilos. All well and good, but I get bored with measuring stuff. And my estimates are occaasionally a bit off (I know how what 300g of flour looks like, but how big is a 250g pile of spinach?)
Elsewhere, they use pounds, shillings, ounce, cups, sticks... whatever came to hand, apparently. "Add three oystershells of parmesan". I don't know how big a stick of butter is, but I know this: I have several cups in my house. They vary from espresso-size to Vente. Which one do I use? Whichever one, you can guarantee it's not regulation size.

So I propose the following: All dry goods should be measured in handfuls. The obvious benefit is that it is quick, and fun. It doesn't matter how big your hand is - if you use the same hand for everything, the recipe balances out. It requires no special equipment and therefore less washing up.

Liquids aren't easy to hold in your hand. They can be measured in 'mouthfuls'. This has the benefit that it is pretty well related to your hand size (unless you're completely out of proportion) and so everything stays in the correct ratio.

I realize this is a bit of a let's all - I did think about changing it to be a set of kitchen scales that displayed the weight in 'handfuls', but I realized that would be utterly and completely pointless.