During my first year in culinary school, a classmate invited me over to make a bûche de Noël, the traditional French Christmas cake shaped like a yule log. I'd never made one before, but he claimed to be a pro at it and wanted to show me how it was done. We had a lot of fun drinking eggnog, making meringue mushrooms, and putting together our kitschy, retro bûches. They ended up looking great but didn't taste very good, thanks to the revolting shortening-based icing that my classmate whipped up (we hadn't had any pastry classes yet, so real buttercream wasn't in either of our repertoires).
Those memories came back to me when I clicked onto this step-by-step photo sequence of assembling a bûche de Noël from Joe Pastry. This post has several good technique tips, and it might just inspire you to try your hand at making a bûche this year. I know it has me thinking about making one—it's been almost 15 years since the Crisco log, and this one is made with real espresso buttercream.
Joe provides recipes for the components, but I had to scroll around a little to locate the instructions for making the decorations. Eventually I found his recipe for French meringue and photos of making the meringue mushrooms, plus photos of making marzipan for the leaves and the marzipan recipe. A bûche de Noël is a bit of a project, but you can make most of the components in advance, leaving the fun of assembly for Christmas time.