Last year we used this book, which was pretty good. The kids were engaged in the story of a grumpy woodcarver who talks to a little boy about each story as he carves it. I would say this is a way to do the Jesse Tree that is accessible to younger kids.
As far as the tree itself goes, we have been gathering ornaments for a few years, but some of them are really hard to find, and I haven't had the energy to devote to making ornaments. My sister is sewing beautiful ones out of felt, but I just don't have the artistic talent to design them nor the inclination to sew them.
But this year I discovered this printable from Ann Voskamp that I just love. So I subscribed to her blog (which I read pretty often anyway) so I could get access to it. I think I've finally discovered some paper Jesse Tree ornaments that I like.
I'd encourage you to find a way to do the Jesse Tree that works for you. It's a great way to keep the true meaning of Christmas in your mind and heart throughout the season. And if you haven't done it before, now is a great time to start making plans and finding ornaments--Christmas will be upon us before you know it!