This is one I use. I dunno if it works and it's a bit "blingy racer boy". On the other hand, why would a thief try to steal something that's labelled? Here's the pic. Just an idea. No harm done.
Blinky lights are installed in every modern car with a security system. Why not add one to your scoot? Does the thief know it's fake? Hell, maybe it's a fake blinky on a bike with a transmitting alarm! Is he gonna take the time to investigate? Nah, he'll generally just look for an easier one to hoist.
Radio Shack sells a blinking light kit that uses a 9 volt battery to keep it running. You can cut the battery holder off the little circuit board and you'll have the blinky part left. This can be wired directly to the bike's battery for a perma-blinky, or you can build a little circuit with a relay that opens up when you turn on the bike. This will make the blinky turn off when the bike is running. It can be irritating to have a blinky running while you ride, particularly at night. Use the comments utility if you need a circuit description.
I'm not gonna spend any time discussing locks, cables, alarms or any of the commercial solutions available to the modern motorcyclist. I will, however, discuss two seldom-considered concepts.
1) I almost never lock the bars with the ignition assembly. I've had two bikes recovered from thefts with the ignition units broken off because the thief pulled the handlebars hard enough to break the cheap aluminum casting of the ignition unit. This gives the thief enough wire and easy access to hot-wire the bike and ride away. No more, thanks.
2) Automatic garage doors. Modern mechanical garage door units have a safety release mechanism that allows the door to be opened manually. This is mandated as a red cord with a small handle on the end to facilitate use by an adult. It's mounted on the travelling part of the opener mechanism. Yup, go in the garage right now, find the red cord with the red handle and cut the damned handle off! Leave the cord there, just remove the handle from the end.
Why? Crooks have been known to use a coat hanger to fish through the top of your garage door. Then hook onto the cord, let the coat hanger hook the handle, then open your garage door easily from the outside.
Yup, it's COMMON. Do it now. Protect your stuff and your family.