The first big project is to clean your yard from anything loose.
Outdoor furniture, barbeque, bicycles, toys, anything else including the old fence poles sitting in the corner of the back yard - you don't do this (only) to protect your outdoor furniture - more than anything you do this to protect your house from flying debris that can break your windows so the damaging winds get in.
Everything loose from the yard has to be put in to the house or even better if you have a shed.
2. Boat and Caravan
If you have a caravan or a boat - they need to be either garaged or tied up.
If they are outside you want to make them heavy, which makes them more stable, and you can do that by filling the van's water tank, and filling the bottom of the boat with water. And you can also use both as places to put your things from your yard, which also adds to the weight.
With your boat, if you are making it heavy you should take it off the trailer or else the weight may break the axles or springs of your trailer.
Place your boat on the ground, away from trees that could fall over it, face it in the direction where the wind will come from, and tie it to the most secure objects around, and also to the trailer to make both more stable.
Remove all the radios, GPS and any other valuable electrical equipment from the boat - it would be costly if they broke in the winds.
If you do leave your boat on the trailer, let the tyres down and place wooden blocks between the axle inside each wheel and the frame member. To make it stronger for the weight, force the wedges into the springs to distribute the weight on the axle.
3. Your windows
Ideally you would have window shutters or cover them with timber sheets but better than nothing is to make a cross (X) with duct tape across your windows.
4. Your vehicle
Your car should have the tank full of fuel, and be parked under cover if possible. If not you could secure it by hooking it to the van or your boat trailer, you could also tie it up as well, and like with the boat and the van make it heavy by filling with things that need to be tucked away anyway (read #5 before you start doing that).
5. Important Things and Documents
Go inside and have a look around at your things - anything extra close to your heart? Tuck it away extra well - under the matress, put it into a plastic bag or waterproof container and wrap in towels - OR even better: this is where your vehicle becomes the best place for things close to your heart including your family photo albums and also important documents you cannot afford to lose.
I could never promise 100%, but I have seen a heck of a lot more broken house windows and lost roofs than broken car windows after cyclones. A car can be knocked over or to its side, but rarely do you see the windows broken and water inside. Before Ita I put all my office contents into our vehicle and felt good about it.
6. Electrical Equipment
The more electrical equipment you can turn off and unplug the better (or you risk to wreck them) - and that includes your fridge. Also after a strong cyclone your power is most likely gone anyway.
Food safety becomes an issue. Fridge stuff needs to get eaten before the cyclone or thrown away - don't eat food that needs to be refrigerated from your fridge after a night it was off - you risk to get sick (with some foods that is to say the least).
You can extend the lifetime of your food by freezing water before the cyclone, and then just putting the ice inside the fridge (in a bucket or something) or an esky, but the temperature in there should not be higher than five degrees Celcius.
Also with strong cyclones typically your town's water system also fails. One thing is your drinking water that needs to be clean, other thing is the water you need to flush your toilet. For the first - fill some clean containers, for the second - fill your bathtub, your wheelie bin, and any buckets you have around.
8. Turn the power off
your fridge also turn
off AND unplug your TV, computers and other
You are actually best off to turn off the power altogether - and even
if you do that, still do also unplug everything. After you unplug your
TV, go out and lower the aerial or satellite dish.
9. Cyclone Kit
Prepare your cyclone kit and fully charge your mobile phone, camera and lap top batteries.