Altering men's pants can be a great way to save money, whether you are refitting an entire wardrobe of favorite clothing due to weight loss or making a new pair of pants fit just a little bit better. The ability to tailor clothing is quickly becoming a lost art, but just a small amount of practice will have you producing professional looking results very quickly.
Make pant legs longer by ripping out the seams in the hems around the cuff at the base of the leg. Have the owner wear the pants, determine where the correct length should be, and mark this length with the chalk. Pin it in place all around the cuff, with the extra material folded inside the pant leg. Iron the fold so that it looks professional, then sew it around the bottom of the pant leg. Cut off any excess fabric.
To shorten the legs of pants, have the owner put them on, then fold the extra material inside the pant leg and pin it into place. Iron the fold for a professional look and sew the hem around the cuff. Cut off extra material. The circumference of the pant legs can also be tightened by ripping the outseam that runs along the outside of the leg, pinning it so that it fits more tightly along the leg, and resewing the seam to give a skinnier, more closely fitting pant leg.
Decrease the size of the waist by having the owner put the pants on inside out. Pull the extra waist material up in a fold at the back of the pants or on the sides, whichever works best with the creases of the pants. Pin the fold in place, and iron it for a better appearance. Sew it tightly with multiple passes to ensure a tight fit. If the pants will be tightened considerably, you may have to rip open the seams and cut out some of the material so that the fabric does not bunch up around the waist.