Oh my, the number of these kinds of things that I've grown up with or seen around me. Coming from a culture steeped in superstition, I grew up around a lot of these do's and don'ts. The ones I mention here are specifically Hindu.

Here's a list off the top of my head:

Eating or drinking during an eclipse will upset your stomach because food gets spoilt during an eclipse. (Debunked. I've eaten during an eclipse and didn't shatter into pieces)

Hair should not be cut on Tuesdays because Mars might be in a bad position and it's bad luck for you. (Debunked. Apparently, most barbers just used to take Tuesdays off.)

Breaking mirrors on Friday will cause a break in your family. (Debunked. I once broke a mirror on a Friday by accident and I'm happy to say I'm still part of one happy family)

Nails should not be cut after 6pm. If other people happen to touch your cut nails, poverty will befall you. (Shit, maybe this is the real reason why I have no savings)

When on their period, girls should stay in a separate room, eat food off a 'period plate' and not touch any other members of the family - for her own health.

If you have a coughing fit, it means someone is thinking of you. (How do you even debunk this kind of thing?)

But you get the gist.