This is how I make reusable gift bags.
a piece of fabric that is 2-3 times longer than it is wide
rope or ribbon for the drawstring that is 4 times the width of your fabric.
sewing machine, thread, measuring tool, marking tool, pins, tape, large safety pin, and pinking shears (optional).
To Make Bag:
1. Finish the top edges (and possibly side) of your bag using either an edge finishing stitch, peeking sheers, or a narrow hem. If the top edges are selvedges, I usually leave them and call it good. If I'm using a highly fraying fabric, I will finish the side edges also with an edge finishing stitch. For cottons, I finish the side edges with pinking shears later on.
3. You will need to mark where you want the rope to come out of the bag and leave a break in your stitching there. On both sides of the fabric, mark at about 3 3/4 in and 3 in from the top of your fabric, creating a 3/4 in hole. For larger bags, you may want to mark further down and possibly have a 1 in or larger hole.
4. Sew up the sides, breaking the stitch between the markings.
5. Trim with pinking shears. Iron seam open.
6. We want to sew the seam down on either side of the rope hole (or you'll regret it later as it will pull through with the drawstring).
7. Fold down top edge with wrong sides together, overlapping rope holes by at least 1/4 in. Measure to make sure it's even.
8. Mark location of rope holes by poking pins from the inside out, and marking with fabric marking tool.
9. Sew stitches across mouth of bag on either side of rope holes.
10. Turn bag right side out.
To Thread Drawstrings:
This requires two drawstrings, each double the width of your bag.
1. To cut your rope, first tightly wrap a small piece of tape around where you are cutting. Cut in the middle. This way, you avoid instant annoying fraying.
2. Attach a large safety pin to the end of one of your ropes, behind the tape.
3. Thread it though the rope hole, all the way around until it meets back at the other end of the rope.
4. Tie rope ends together.
5. Attach safety pin to the other rope in the same manner. Thread it through the hole where your other rope ends are not coming out.
HINT: To make life easier, you can now pull the loop end of your first rope through and attach the safety pin near the tied end of the first rope and use it to pull your second rope through.
6. Second rope threads all the way through and is tied at the opposite hole from your first rope.
I gave away this little bag as a wedding present to dress up the otherwise boring card and money.