Wood workers? advice needed

So like most in this hobby I dream of a nice looking humi someday. So I figure I am going to try and make one. I think I need to just try and make a few smaller boxes to get the whole wood working thing down before I go for something bigger.

So on to the reason for the post. Has anyone made their own box joint template? I really like the way box joints look when put together with multi layered woods. Kinda like this.


I have stated looking into making my own template but I may end up having to just buy the things they sell for doing the joints. Does anyone have and use them? Kinda like this one. http://www.hartvilletool.com/product/10973

Any advice for a future wood worker?