It never ceases to amaze me that the most mundane of chores can have a whole raft of folklore attached to it. I encountered the following rhyme from some folk related tome I read ages ago about how the day you choose to cut your nails can make all of the difference [who knew!!]
"Cut them on Monday you cut them for health
Cut them on Tuesday you cut them for wealth
Cut them on Wednesday you cut them for news
Cut them on Thursday a new pair of shoes
Cut them on Friday you cut them for sorrow
Cut them on Saturday see your true love tomorrow
Cut them on Sunday the devil will be with you all week."
If you've got white marks on your nails heaven help you- the outcome really depends where you land. A couple of examples are in Japan it means a new set of clothes is winging its way to you whereas in Massachusetts it's indicative of how many fibs you've told.
You don't want ridges on your nails...that foretells of approaching death whereas if you have a prominent half moon at the nail base this means you're of good stock.
If you want to harm somebody else try walking over the nails of that particular individual but remember you need to be in Germany for that one to work.
You can even tell the character of a person by their nails. One who has broad nails has a gentle disposition whereas small nails means they are obstinate and angry. Absolutely what you don't want is someone with black nails as this means you're dealing with a cheat or perhaps someone with a love of gardening or even poor hygiene. In the immortal words of my great grandmother when she saw a fellow with dirty nails travelling on the bus "that chap's nails are so muddy you could grow peas under them."
Evidently it is a matter fraught with danger beware!