This project works best with images that have straight lines so geometric images or svgs are perfect for this.  

Your hole size will be determined by your wire size and how many wires go into each hole.  The hole size needs to be the number of wires going into the hole times the thickness of the wire plus a little extra margin for ease of movement.  My wire was .5mm so I decided that .7mm for a single wire was perfect but at 5 wires (.5 * 5) adding .4 made it still pretty easy to move them around.  If you aren't sure of the size you want it's a good idea to make a little test piece with each hole size so you can test the fit.  The most wires going into a single hole on this project was 5 so my sizes are .7, 1.2, 1.8, 2.4, and 2.9mm  

Can you make them all the same size?  Yes.  But I wanted the least amount of hole to show as possible so I sized down anywhere possible.

Import your image and create 1 circle in each size you'll need

The easiest way for me to do this was to copy the circle for 2 wires and then paste it on every point where only 2 wires will meet.  Then copy the circle for 3 wires and paste it on the points where 3 wires meet and so on and so forth.  After you have pasted every point onto your image go back and review the whole thing to check if you missed any or if you want to make any adjustments to the shape.

Select your svg and give it an outline.  I went with 3mm for my 12" gecko but for larger projects you may want a wider trim size.  Select all of the circles and unite them and then subtract them from the outline.  You now have 1 object to set to cut.  Change the original image to Ignore.  You will want to keep it so you can reference back to it when you are trying to remember which holes are connected by wires later.

You are ready to cut this out.

You can paint the board before if you'd rather but I like to just paint what I'm using so I can use the rest of the wood for other projects later.  I gave it 2 coats of paint, allowing it to dry between coats.

I chose a copper colored wire that I thought would show nicely against the blue background.  I would cut pieces of wire about a foot or two long at a time for ease of work and push it back and forth through each hole like embroidering.

I used a couple different kinds of plyers and some snips to help me pull it through, shape it, and trim pieces.  If you have sensitive hands you may want work gloves and your hands can get a little raw from the repeated pulling of the wire.  

The ends of the wire can just be folded over and don't require tying since this will be an art piece.  It holds its shape well.

You will most likely hang this on a wall so now you can attach a hook of some kind to the back, find a place to display it, and hang it up.