THE SUIT DROP
The drop is an element that characterizes the difference in size between pants and jacket. For example, some brands offer a drop of 6 (pants in 36 and jacket in 42), while others offer a drop of 8.
Once you have found a jacket in your size, it is possible that the pants associated with it do not fit (bad drop). Fortunately, it is the easiest piece to retouch.
THE SIZE OF THE SUIT PANTS
A good way to check that the pants are not too small for you is to observe the opening of their pockets: whether it is in front or behind, the pockets should not yawn, but remain perfectly flattened.
Concerning the length of the pants, it is the position of the hem that is decisive: the leg must fall straight, and form a single fold (called breakaway fold), at the bottom of the pants.
Not respecting this rule exposes you to the risk of packing your leg by accumulating folds on the shoes (pants too long), or to show off your socks in a suspicious manner (pants too short).
By the way, if you want to gain a level in sewing, you can learn how to make your invisible hem by rereading the article I wrote on this subject.
THE CROTCH AND BOTTOM OF THE PANTS
Pay attention to the purchase, you will notice that the pants sometimes tend to be a little loose at the crotch and under the buttocks.
In such a case, it is necessary to make a touch-up to avoid the parachute effect - an unfortunate effect, since it doesn't even slow down an accidental fall.
Make sure that the retouch does not shorten excessively, otherwise the crotch of your pants will wear out and crack prematurely.
It's all a matter of measurement for the tightness of the pants: if you tend to wear out the crotch of your pants quickly, then take the side of a little more material at this level.
THE FUSELAGE OF THE LEGS
A slightly curved drop of pants tends to enhance the silhouette. If your pants do not naturally tend to taper towards the shoe, once is not customary: your retoucher will be able to taper the legs.
Here, as always, it's all about subtlety. Don't look for matchstick legs worthy of slim jeans.