For maximum efficiency with cutting printables, consider in investing in a cutting tool like the Silhouette Cameo or Cricut Explore. Both allow you to print out any shape and cut around the printable. It takes minutes to set up the file and cut compared to hours of using scissors.
Adobe Illustrator is the best option because graphics are vectors, meaning you can size and resize your images without making them pixelated. You can create poster sized images or cake toppers with the same graphic and the quality of the graphic won't be affected.