Felled SeamOne of the challenges when hand-sewing (or any sewing for that matter) is how to make strong seams. There are many different stitches to use. I like to use a running stitch to make a felled seam and I use it for almost all my jersey clothing construction. It's fast and durable. (The seams for my spiral scarf are made the same way.) It'll take a lot of use and washing and has never let me down. It's also good for linen and denim fabrics. You'll probably find this kind of seam on some of your pants. For this demonstration, I've used thick contrasting embroidery floss, to illustrate the process:
1. and 2. Sew two pieces of fabric with a simple running stitch, right sides together.
3. Lay the seam flat to one side and top stitch through all 3 layers close to the first running stitch.
4. This is how the stitch looks from the right side. Just like the seam of you denim pants.
This seam is relatively fast and holds together very well, because it's double stitched.
Half French SeamThe seam above is a half french seam and I use it in my pojagis: It makes the fabric reversible and you can work the seam in many different ways.
1. It is important to allow for a generous seam allowance - double as much as you would normally use - and sew the the two pieces together (I use a running stitch).
2. Cut one of the two edges of the seam allowance in half.
3. This is how the seam looks with one edge cut.
4. You take the longer seam allowance and fold it over the short one, tuck it under and pin it down. (Ironing is also a good idea, one which I only follow occasionally.)
5. and 6. There are may ways to sew the seam down. In image number five I've used a running stitch and in image number six a slip stitch.
7. Image seven shows how the seam looks with half slip stitch and half running stitch.
8. When you are finished and hold the fabric against the light, the seam will be darker and the effect is quite stunning.
This seam is perfect for patchwork and delicate fabric like linen or silk. Other possible applications are curtains or lampshades or any situation where you want to play with light and shadow. I've also seen it in clothing construction.
One common assumption is that hand-sewn seams are not strong enough for clothing. Not in my experience. I've never had one of these seams come apart.
With these two seams, you are ready to hand-sew your own clothing!