Proper bleeds for print can be a little confusing. We'll try to simply things for you with some explanation and visuals. You'll leave here with a good understanding what printers like us would need in your designs to help us give you everything you expect.
All you really need to do to get started with special colors such as White, Clear and Metallics is to create some custom spot colors. We'll teach you how to do this and what to keep in mind while designing. You'll need a decent design software that will allow you to create custom spots and while it's not necessary, layering is helpful.
Ultimately, we need a PDF file. Our print server will only understand and work with this format. While we can take just about any file format, the best practice is for the PDF to come from you. We can do conversions for you which may add costs to your project. Bad things can also happen to your content. Text change appearance and even move around unexpectedly. Graphic elements can completely disappear. This will not give you the results you expect and we don't want that. Your satisfaction is of the utmost importance to us. So, if you can, always make your final step before sending us your file, to save as or export as PDF.