When I was active duty and stretching every dollar to the max, I would get a little money put to the side by dumping my change into a jar.

When the jar was full, I'd roll up the change and stash the rolls in an ammo box in my armory. When those small emergencies would arise, after a while, I just pulled the needed rolls out, changed them into dollar bills at the bank.

Being change, that money wasn't touched until I really got into a bind.

That's 1 way to start building an emergency stash of cash.