It depends of you just need something simple or complex. Local sign shops can whip out some easy stuff for you. I've got a sister with 3 laser cutters so she cuts out some things for my boats and trailer. Sign shops try to BS you trying to tell you that they can't do corporate things like Futaba or Airtronics for instance but in reality unless they have a bootleg program the rights have aleady been paid for to use them.
You get get vinyl cut, slide-off water decals or regular printed ones. The slide-offs you can get DIY kits that you can print off yourself on a home printer. Some hobby shops carry the stuff needed.