If you're about to hem your trousers for the first time, be sure to get your measurements right first! You wouldn't want to end up with one leg shorter than the other, would you?
Before hemming, it's vital to have a fitting with the trousers and ideally with shoes. This way, you won't have any unpleasant surprises and the length of the trousers will be perfect.
Traditionally, the hem is made at the heel of the shoe. So, fold the trousers just above the heel and pin.
This pin will be your reference point for the rest of the work. To avoid the two legs having different lengths, we'll pin the second leg at a later stage, when the trousers are flat on the table.
Depending on your style and outfit, you may prefer your trousers to reach well above your ankles.
This is often the case these days, for both men and women.
The important thing is always to take your measurements under the right conditions and again, with the shoes you're most likely to wear with your trousers.
To leave yourself room to change your mind or subsequently your style, make a modifiable hem. That is, rather than cutting your trousers to make your hem, you'll simply turn the fabric back on itself and proceed to sew.
This will allow you to unstitch your hem later, if you want to give your trousers some length!
Beware: a hem is never straight. Trousers are always longer in the back than in the front.
Your crease should therefore be curved (the difference between the front and the back should not exceed 1.5 cm).