I mostly followed Devout's Stealth pad plans, but made a few small changes of my own...
I left a 2 inch spacer around the edge of the pad, I think it looks better, and this means I can butt two next to each other for doubles and have a small gap between them.
The corners are raised (by two sheets of thick cardboard that were placed underneith and screwed down) about 1/4 inch... slightly more than ITG2, but less than most other arcades I've played at (admittedly, that's not many... I've always been a home player)... I never lose my feet on them anyway, even when doing fast doubles...
Each of the corner pieces and the center are made of a nice furniture pine, which has been sanded down to be nicely rounded, then stained and sealed to protect it a little better... it hasn't been beaten up nearly as bad as I thought it would, considering how soft pine is... the only marks on it are the ones I put there accidently during construction... usage hasn't seemed to damage it at all... yet.
I used bolts and nuts with washers to hold the arrow panels to the base... originally, I went with wood screws as devout suggested, but found that after opening up the panels a few times to adjust them, that the wood stripped too fast... bolts let me open and close them multiple times without a problem... plus, you can torque them down more. I used 2" long, 1/4" thick countersinking bolts, but I'd suggest using pan head bolts instead of countersinking, since the sheet metal in a couple of my corners are threatening to punch through...
Rubber furniture grips on the bottom (placed in the four corners, and on either side of each arrow, to support weight better) prevent the pad from slipping around.... I've played 100+ songs in a row without the pad moving.... when doing doubles with both pads, after about 50 songs, there's a half an inch gap between them =P
MadCatz Controllers work great for home pads it turns out... $10 each, and they're easy to solder to.
I drilled a hole in the back of the controllers, and put a Cat-5 cable in, then separated the wires and soldered to the arrows.... amazingly enough, the arrow buttons on the controller still work! Which makes it easy to select songs with the controller, then just put it down and move to the pad to play.
Nice big copper discs to solder to for each arrow and ground.
I used a female Cat-5 data jack to connect the controller to the pad... this way, I can disconnect the controller and not worry about wires pulling in transport.
Yay, sakura! Ok, I'm not very good.... the greats are my fault, not the pads... in fact, I had to practice for 30 mins before I could pull off the AA on sakura at all... *hides*