We have been tweaking our template around to get just the right size bag. This week we made some kid bags, and have been cutting and planning some cool adult gift sets for the holidays. A loves to help sew...although he doesn't go solo of course. He was very excited about this vintage style baseball fabric ("It is odd, I don't like baseball, but I just LOVE this fabric, mom!"). It was a remnant, but we squeezed 2 bags out of it...because what you make for one, you must make for the other! This size is perfect for a few toys, or a nature notebook/crayons/water for a walk, or a few library books. There are even a few pockets on the outside for extras.
A helped sew much of the bag - the easy straight lines and hems are great for that - and when finished had to Ooh and Aah over how it was just the right size, and sling it casually over a shoulder to walk through the house ... trying to see how it looks on him in passing reflections!