I first start with the BEST QUALITY wood I can find.  I use the best quality 1/2" AC plywood from a local yard.

Also, I get the premium handpicked 1" x 4" 's and also 2" x 4" 's.

I'm not going to tell you all the steps or all the tools involved, but here are some basics.

Boards are secured to frame, unpenatrablable by moisture.  All holes are then filled in and sanded down.  Edges and corners are routered smooth.

Boards are primed and then painted, after they are carefully sanded.  Unless they are a stained or natural board, or combination of both as seen below.

After Boards are completed, they are topped with several coats of a clear coat.

Legs have a center support that feature bottle holders and can be notched out for to accomodate hole lights.