What's the best way? I've put numbers/letters together, and they bake and meld together, but they're flimsy and break apart at the seams easily. Anything special about doing this so they're more sturdy?

Thanks!

Can you wet the edges (where they meet) and rub a little to create 'glue' ? I don't put cookies side-to-side, but use that when putting layers together.

I have had luck taking the two cookie cutters, such as a 7 and 8 and drawing a pattern off them. I then lay the paper patterns slightly over the top or bottom of the other pattern and mark the lines. I cut out the marked area and when I cut the cookie dough I lay my paper pattern over the cookie and cut out the little notches with a knife. I lay them together on the cookie sheet like a puzzle and they bake together great. I have made the number 78 and 52 and had great luck. I have pictures of the 78 but do not know how to attach photos yet...Hope this makes sense.