Things You'll Need
Hand sewing needle
A tunic top is generally longer than a normal blouse but not long enough to be a dress. If you have a tunic that's a little too long, you can hem it as you would a skirt or dress. Take in a tunic that's too wide as you would a sweater or blouse. Altering a tunic doesn't require much sewing skill, but you should be able to accurately measure both the garment and the person who will wear it.
Shorten the Tunic
Put the tunic on and note where it falls to on your leg. Measure from the bottom edge of the tunic to where you'd like it to fall. For example, the tunic may fall to your knee while you want it to fall to your mid-thigh. To get the most accurate measurement, you may want to recruit a friend to help you measure.
Take off the tunic and turn it inside out. Lay it flat on a table or the floor.
Measure the amount you want to trim off of the tunic from the hem and draw a line at the point across the width of the tunic.
Trim the extra fabric off of the tunic so that 2 inches extends below the line you drew. If you're shortening the tunic fewer than 2 inches, don't worry about trimming any fabric.
Fold the bottom edge of the tunic up 1 inch, then up another 1 inch. If you're hemming fewer than 2 inches, divide the amount you're hemming by two, then fold. For example, if you're hemming the tunic by 1.5 inches, fold the bottom up 3/4 inch, then another 3/4 inch. Pin the folded portion to hold in place.
Thread the needle and tie a knot in one end of the thread. Push the needle into the tunic so that the knot is on the wrong side. Move the needle over 1/8 inch or less and bring it back through the fabric. On the wrong side of the fabric, move the needle over 1/2 inch, then push it back through to the right side. Make another 1/8-inch stitch. Continue stitching all the way around the hem of the tunic. You're using a blind stitch, which will be nearly invisible on the right side.
Loop the thread through the fabric several times once you've stitched all the way around, then pull the thread through the loops to make a knot. Trim the excess thread.
Take in the Tunic
Wrap the measuring tape around your waist, around your hips and around your chest. Record the measurements.
Turn the tunic inside out and lay it out on a flat surface. Measure across the chest portion of the tunic, across the hips and across the waist. Multiply those measurements by two, then subtract your actual measurements from them. Divide that number by two. For example, your waist may be 28 inches but the waist of your tunic may be 32 inches. You'll have to take the tunic in 4 inches at the waist, or 2 inches on each side of the waist.
Mark on the tunic the amount you'll take in at the chest, waist and hips on each side of the shirt. Draw a curved line connecting the marks. The bottom of the curved line should hit at the hem of the tunic. You can pin the fabric together along the line.
Stitch along the curved line on each side using your sewing machine.
Turn the tunic right side out and try it on. You may need to take in more or let the tunic out a bit.