Barb, I stitched in the last one in each row and then chained 2 for the first stitch of the next row.
Jane, I do not think I would do an alphabet block. I would probably go NUTS!! This was not as easy and "do without thinking" as the stuff I normally do so it took more time. My daughter loved it though so I may tweak it a bit and make her a baby doll blanket with a BIG heart in the middle. Pretty sure I have enough scraps of some colors she likes for that.
On the editing. I cropped my pics in Microsoft Photo Editor and then added the words and arrows in Microsoft Image Composer. You can do that in Paint also but for some reason that is no longer on my computer.
Here is what I have been working on this weekend, I am using the same theory to change colors in this one. It is 4 feet wide and will be a lap balnket. I am using all of my leftover bits of yarn for the colors and the tons of black I have. I am using one thread of black to go back and forth the entire length and a separate thread of black for each side, then the 4th thread for the middle color row. So I am not cutting and knotting the blacks since I leave them hanging until I get back to them. Same goes for the 2nd row of each color, I just let it sit until I come back and pick it up on the next row. So far this one is about 2 feet long.