For Thing 1's birthday party, I bought paper gift bags that I customized with printed tags. For Thing 2's birthday party, I decided that I would rather sew reusable cloth bags that hopefully would be useful later for holding treasures. Of course, I came up with this brilliant idea somewhat at the last minute, so they had to be easy-peasy.
Hancock Fabrics had their relatively cheap broadcloth on sale, so I had Thing 2 pick out four colors. His brother helped, and together they chose green, blue, red, and orange. Nice, bright colors! I was concerned that the fabric would be too thin to be really sturdy for bags, so I chose plain muslin to line them. That also meant that I didn't have to worry about seam finishes. ;)
These are very simple bags: basically, the linings were squares with squares cut out of the bottom corners for boxing them. For the outer fabrics, I added an inch and a half in length for folding over the tops to the inside and covering the top edge of the lining. I could have simply sewed them right sides together and then turned them right sides out, but that would have meant handsewing an opening shut in the lining. I didn't want to deal with that, and I wanted to try this. The raw edges of the handles were tucked under the outer fabric, when it was folded to the inside (does that make sense?), and then stitched in place when I stitched next to the fold on the inside. Then I folded the handles back up over the top of the bag and topstitched around the top of the bag. So that stitching also holds the handles in place. I would have done an "X" over where the handles attach if I thought these bags would be used for really heavy treasures. But given the size of the bags (I think they ended up something like 7 inches wide, 9 inches tall, and 4 inches deep.), I didn't think that they'd ever have to hold anything too heavy.
I hadn't figured out the sizes for the bags when I bought the fabric (brilliant, huh?), so I bought 1.5 yards of each color broadcloth and then 6 yards of muslin. In the end, that gave me 3 of each color bag, plus some leftover of each color. I have probably half the muslin left, because I could get 3 lining pieces to fit on it width-wise. (Of course, then we ended up having only four kids at the party, due to illness and scheduling conflicts, so now I have eight bags stashed in my gift stash.) I thought that this project turned out really well, and I do hope that the kids have been using their gift bags for books/toys/whatever.