Polka Dot Peril

There are some prints in the rockabilly fashion world that are known to be "rockabilly" in style even by the mainstream, such as cherries, skulls, tattoos and POLKA DOTS!
All of these can be used unwisely at any age, but none so much as the polka dot - it is very easy to look like Minnie Mouse. This is especially tragic if you end up looking like an OLD Minnie Mouse.
There is a good rule you can go by, however, that will let you avoid that fate:

The older you are, the smaller your dots should be.

For example, if you're under 20, go ahead and go large - this is the age when you can get away with it to some extent (you still do risk looking like you're "costuming" so be forewarned!). At 30, take it down a notch - your dots should be about not much more than 10mm in diameter. At 40, you're in dangerous territory - your dots should be very small, 1cm in diameter or less. And at 50, they should disappear all together. Don't worry, you'll be able to wear dots again, after age 70, when you can play the part of wacky old lady!

NO ONE should be wearing this above the age of 5...

Large dots = under 20 years old only

1930s-1940s dots. Over 40s, go for it!

Don't try this at home. Double whammy: crazy big bow, with
equally crazy big polka dots.

Late 1930s dots, appropriate for any age.
This dress is nice, but a little too long for my taste.

There are exceptions to the rule, such as wearing dots of varying sizes in the same print (which does take it away from classic dot print). You see a lot of this in 1930s clothing, and it works well for any age. The other exception is if the dots are all the same size, but are scattered randomly. The costume element of the dots is all but removed in these instances.

So watch your dots, and watch your dignity!