Dear, PCB is for using, not for beauty, most PCBs have silkscreen layer. You can design whatever you want and send designed files to PCB manufacturers, some small Companies will be happy to make your PCBs.
Good looking PCBs come down to know-how and practice.
Check out some of my designs: http://www.crossroadsfencing.com/BobuinoRev17/
Like this one that combines SMD and thru hole for the various functions:
My advice is to choose a very simple design with only a few parts. I would recommend a relay, but like everyone says, be careful with mains power.
Aside from getting the component footprint correct, you need to know the correct trace width and required clearance between traces. There are many online calculators for these. The smaller grid you use, the closer you can get the traces. Arduino has very close traces, which makes it look clean.
You can then choose the color of the board, but this adds cost, so don't do it on the first ones when you might just be printing out expensive coasters bc they might not work. I do my first runs on OSHPark. They are cheap, but the only color you get is purple. The nice thing I've found with OSHPark over the others that I've used is that you can upload an Eagle file direct, and you immediately see what each layer of the board will look like. If how it looks is important to you (it is to me as well, I know it does nothing for function, but I like to put some effort into appearance), then you can see it before you buy it.
Here is a first run board that I created with them:
I've primarily been using Eagle to design my PCBs. I agree that the arduino boards are beautiful, mostly because of the silk screen. If you want to use Eagle, make sure to check out Negasilk. It's a script that generates negative silk screen. I've used it for these boards:
You need to find/pick a PCB design software package
most popular (IMHO) is Eagle. (lots of community support, scripts, and tutorials)
maybe the highest learning curve out of the box/gate? But once you come to terms with the shortcuts and mouse button usage/menus, its a pretty powerful piece of software
Once you are done 'designing' your board/PCB.. you need export some file (commonly referred to as GERBER files)
these gerber files are supplied to the PCB fabrication house that you want to actually MAKE/PRODUCE the PCB's for you.
I personally have used several PCB fab houses
all with more or less the same results.. some have certain perks over the others...but relatively all equal)
"I" choose to go with fab houses located in China... why?
Because the prices (IMHO) cant be beat.
I usually want all my boards to be as small as they can be... usually under 2 x 2 inches or so.
that means (for me).. I get 10 x pcb's.. for roughly $10.00 USD..
iTead Studios
Elechouse
and another place I dont recall.. are the three I have used in the past.