The list is not at all scientific or researched just basically my musings. So in no particular order:
As you approach do you see
You might have a crunchy mama. This is known as babywearing. Notice there is no stroller but baby is on mama's back sound asleep.
You might also notice that baby has a necklace made of amber. This is known as an Amber teething necklace. It helps with teething and growing pains. Yes it works why would crunchy mama spend the money otherwise? Here is a pic:
Does the baby have a very big butt? This could be the sign of a cloth diaper! Yes they make them and people buy and use them. Most crunchies who cloth diaper can't believe anyone would choose to use disposables, what a waste of money and talk about bad for the environment! Beware discussing cloth vs disposables, a crunchy has researched this topic and can talk for hours!
You might also notice the lack of bottles or pacis. Many crunchies refuse to use either. This crunchy uses both but if I'm with baby you won't usually see a bottle cause I just wipe out a boob to feed the baby. You might just see a boob or two if baby/toddler is very active. Do not be afraid. We don't mind and are use to it. Please ask away but be ready for lots of info! This too is a topic of research!
See by no means a complete list. See what else comes to mind? How can we head a mainstream mama spot the crunchy?