Years ago I attended a seminar about styling, power dressing, dressing for success (it was the early nineties!) I still remember vividly being told never to carry a briefcase or handbag wider than your hips unless you wanted to add width to yourself.
Does that even hold true anymore? I guess the skinny celebrities with giant handbags can afford to add more bulk to their delicate frames.
When designing bags for kids the dimensions are important. Sometimes what I think looks like a very small bag really swims on Little Guy or vice versa on Biggie.
In this picture I asked Biggie to hold this instant soup box while I checked its dimensions on him. It's roughly the size of my small toddler messenger bags yet still fits Biggie's proportions. It's my sewing tip of the day. Do mock-up test run before you cut and sew your precious fabric.