Thanks everyone. I successfully added velcro to the top of the 2 laptop bags I made recently. I did my personal bag first (in case I did it wrong) but it came out ok so I did the gift bag too. Like Bear said, the stiching shows, but I also was very neat and I don't think it looks bad - it just shows.
So thanks again. Knowing how to properly attach velcro opens up a whole new world of possibilities for me. Such a simple thing really, but it totally confounded me!