French seams are such a pleasant way to finish the insides of a bag or garment. And the truth is, they don't have to take that much time.
Here is a quick photo guide on how to sew French seams without any trimming or ironing or pining.
Step 1: Place wrong sides together and line up the edges of the seam you want to sew.
Step 2: Sew the pieces together with a 1/4" seam allowance. Depending on the thickness of the fabric you are using and its propensity to fray, you may want to increase the allowance of the seam a little bit.
Step 3: Turn inside out so the right sides are together.
Step 4: Press the seam flat with your fingers up and down the whole length of the seam.
Step 5: Sew over the same seam with a 3/8" seam allowance. Again, depending on the thickness of the fabric you may want to increase the seam allowance slightly. Just be sure that whatever allowance you used on the first seam, you use a slightly larger allowance on this second seam.
Step 6: Admire your beautifully finished seam!