Decals... Possible, but with limitations. The "pro" custom decals you may see here are most likely composed in a computer art program such as Corel Draw. Those take time to master. Harry, our moderator has done a tutorial on the process.
Now, even IF you had all that skill, you would still need something called an ALPS Printer... which are no longer made. Plus, very difficult to buy supplies for.
However- you can still print decals! Just no white, shiny gold or silver. White or clear decal film is available that can be used. Some will run it through their home printer, then top coat it with a fixative spray. I prefer to print my art on a 'master', then take it; and my decal film to a copy house, and let them print it. Expect some hesitation from leery employees, who worry that the decal will foul their copier. I have never had a problem with that. Works fine every time.