DIY discussion almost invariably has a pinned thread about this sort of question—
this one should get you started.
Personally, I almost always order pre-finished, powder coated enclosures. Sometimes I'll apply a waterslide decal and then clear coat over it. I'm gearing up to do a small production run in the coming months and in that case I'll have my enclosures professionally printed, most likely by Pedal Parts Plus.
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Bikers have more fun that people do.
Free "open source" EagleCAD files:
99ZuluFX