Following is a step by step tutorial on how I do my in-seam pockets. Of course there might be other better ways but this is how I do it.
Start with 4 pcs of pockets all cut and serge or zig-zag around the curvy edges of all the pieces
I get dyslexic sometimes so I have to lay it out carefully. Lay it with right sides facing up
Turn the pocket to the side seam, right sides together and pin. Ensure that the pocket is placed at the same distance from the waist for all 4 pockets.
Sew the pocket to the side seam using a 3/8" seam allowance, back stitch both the beginning and end.
Serge or zig-zag the whole side seam
Press the pocket piece back out. Repeat all the steps above for all 4 sides of the shorts.
Now place the pocket attached shorts pieces right side together ensuring the pockets and waist line matches.
Sew the side seam from the waist to the top of the pocket opening a 5/8" seam allowance, back-stitch at both ends. Mark a point with chalk 5.5" - 6", below this backstitched point. This will be the pocket opening and will not be stitched. Then stitch again from the top of pocket bag, around the curve of the pocket bag and back onto the side seams. Leave your needle in the down position, pivot at the mark that you made earlier and continue stitching the bottom portion of the pocket and side seam at 5/8" seam allowance. End with a back stitch. Repeat this for the other side of your shorts.
Press the seams and pocket bag to the front. Sew your waistband as directed in the pattern and ensure that the top portion of the pocket is caught within the waistband stitching.
Turn your shorts right side out and press your pockets and side seams. You will notice a 1/4" overhang of the front side of the seam. This will give a nice flush and avoid any peekaboo of the pocket fabric if you are using a different fabric from the main. That's it and you now have some pretty neat in-seam pockets!
If you have any questions please to do hesitate to leave me a comment.
I will be conducting the Moji Pants class at Yee Button on 20th February 2016 (Saturday). For more info please click my Facebook Event Moji.