LENGTH & SHAPE
The most flattering length is no longer than under half a millimeter. Its clean and it won't get in the way much compared to longer nails, obviously.
The most flattering nail shape (to me) is called a "squoval", which is square-oval. Usually shaping your nails into a mirror image of your cuticles.
To get the look, file your nails straight across going the same direction. That way you have more control on how much you file off. Then, round the corners. More round than square.If you're going to the nail salon, ask for "square-round". Which will be more square than round. Then ask them to round it a little more.
If they don't understand you, ask for square, then tell them to round the corners more. My nails are a little more square than oval. So, I don't know why I put "squoval". The photo below my nails are more of a squoval shape.
Note: if you want your nails a certain shape, but your nails are too short,grow your nails first! Nail salons will not be able to achieve what youwant if it's not possible with nails they can't work with -- Neither will you.
Bright colors on your fingernails aren't as flattering as you may think. They're nice for your toes though. There are certain reds that compliment every skin tone. If you have fair skin, firetruck red would look great. If you're medium, blood red would be flattering. And garnet would be nice for darker skin tones. The nail polish I list are only examples of shades.
Have fun experimenting :) !!