There's no magic formula for finding the perfect pair of jeans; you must have to keep trying on pairs and pairs until you find the right one. However, you should keep in mind your body type and which part of your body your want to flatter.

Petite Figure
The petite body type comes in all shapes so it's difficult to find the correct fit and the right length. Make sure the waistband work for you and is in proportion to your body type.
Opt for narrow leg cuts, by going for skinny, straight and slightly boot cut depending on your curves.
For additional height, iron a crease down the front of your dark jeans and team with heels for a few extra inches.
Wear heels also with skinny jeans and keep the length long as the excess fabric at the ankle gives the illusion of longer legs.
Opt for jeans with flat pockets, with minimum fuss that keeps the proportion of your petite figure.

How to buy jeans for your body type
Pear Shape
Women who generally have slightly wider hips then shoulders, slimmer upper body but fuller in the hip and thigh area, are considered to be the pear shape body type.
Your goal is to draw attention away from your curvy hips and accentuate your legs.
Go for wider waistband that sits on your hips with higher back rise. Your pear shape also benefits from slimming dark washes, flared jeans that lengthen your legs still balancing out your curves giving a sexy look.

Hourglass Shape
Your bust and hips are about the same size, but the waist being about 10 inches smaller. It's important to add balance to your curves and the best way to do this is a boot cut or flare leg.
Choose jeans that are made of stretch denim, these will hug the curves and give a smooth fit at your waistline and hips.

Apple Shape
You hold most of your weight in your upper body, tummy are and bust - but the best part is that most apple shapes have slim legs which open up to a wider selection when shopping for jeans. Don;t go too high with the waistband if you have a short waist and big bust for obvious reasons. Always look for a curved waistband that's higher at the back, for comfort.

Slim and Tall

The upper and lower body are in proportion to each other with a smaller bust. A high-rise jean suit best a tall figure, as it balances long, lean legs with the waist.
How to find the perfect pair of jeans

Fuller Figures
A voluptuous body shape that tend to put on weight all over.
Forget that you need to hide your fuller figure in baggy jeans - as these will make you look and feel bigger than you really are.
Always go for darker denim wash to give a slimmer look, as frosting and fading only enhances and draws the eye to the highlighted area.
Always go for medium or high waist jeans and when buying jeans make sure you sit down with the jeans on before you buy them to check the comfort.
The boot cut is the most flattering of cuts as this balance out curves.
Wide legs are great for chunkier thighs if you keep the leg long and the color dark.
Opt for big pockets, but embellished pockets will only draw attention to the area - so if you're not looking for attention then keep it simple.