INVERTED TRIANGLE SHAPED FACE
If your forehead is the widest part of your face, tapering down to a narrower, pointy chin, then you have an inverted triangle face shape. This shape is similar to a heart-shaped face, but the difference is that the heart shape is shorter and there is usually a widow’s peak.
To balance the inverted triangle shaped face shape, choose earrings that de-emphasize the wide forehead, and create the illusion of width at the jawline. Chandelier or teardrop earrings work well. 

OVAL FACE
Is your face oval like an egg? You can wear almost any shape, but triangular earrings or simple studs will show off your lovely cheekbones best!

ROUND FACE
If your face is circular, meaning widest at the cheekbones with no taper to the chin, then you have a round face.
Drop or dangle earrings will elongate your face and make it look slimmer. Avoid large circular earrings, hoops and button studs which only emphasize the roundness. Also, stay away from drop earrings with a dangling round disc. The roundness will only make your face look rounder.

HEART SHAPED FACE
If your forehead is wider than your cheeks and the lower half of your face narrows like a heart then you have a heart-shaped face.
In this case, you need to counterbalance your sharp chin with chandelier or teardrop earrings. Earrings that are wider at the bottom than the top help fill in the lower portion of your face, so your face is more balanced.

LONG AND NARROW FACE
If you have a long, thin face choose earrings that emphasize the width of your face.
Studs, clustered earrings, short dangles, hoops in a medium to large size. Any time of round earrings will widen your face, and make it look fuller.

SQUARE FACE
Gals with wide square jaws ( forehead and jawline are similar widths) need to soften the hard edges of their face. 
To do this, go for earrings that are medium to long with rounded edges. Oval shapes soften things up, and circular earrings and hoop earrings work well too. Stay away from square studs or any kind of earring with a square as it only reinforces the squareness.

WEAR EARRINGS THAT SUIT YOUR LIFESTYLE

Where will you be wearing the earrings?
Work or Office: The more conservative the office, the more conservative the earring.  Choose classic styles in gold for the most authority. Executive dressing means no dangly or hoop earrings.  Avoid large earrings if you are in very traditional, conservative fields like finance and law.
After Work: Now’s the time to loosen up and show your personality. You can forget the simple studs and have some fun.

Earrings clasps

There are various types of earrings clasps. There are some examples for you: