The most important thing when lighting cakes is making sure they are stable and aren't at risk of tipping over. To that end, I've built some 2' by 4' platforms that I create "sets" of 500 gram and 200 gram cakes for my displays. I like to put both 200 gram and 500 gram in the same set to fill the sky from bottom to top. This first video talks about how I design and lay out a set.
This next video is pretty simple, it shows how I duct tape the cakes to the platform and each other for stability.
Here we get to the actual fusing of the cakes. It's important to always burn INTO the fuse so you don't risk the fuse falling off and not igniting the cake.