As an ex- professional valeter I can safely say that many of the more expensive products on the market cannot justify their prices, and that the secret is definitely in the method not the products (although they can help).
First of all, probably the most important stage, use plenty of water to spray off the car. Use hot water if you can, preferably using a pressure washer. Use a shampoo that contains wax (most do these days, for a non- smear finish I recommend using Turtle's Extreme Wax Rapid Dry formula) - use a generous amount, again in a bucket of warm water. Once car is fully shampooed you can use the same bucket to clean the alloys. If shampoo is not enough as you have let brake- dust accumulate, use a light alloy acid, although I don't like using this as over time it corrodes some metals, especially wheel nuts. Rinse off thoroughly, then I use a product called Rapid Dry which is basically just a soft silicon blade with a handle to wipe of the water quickly. This saves time and leaves a slicker finish, I highly recommend. Alternatively you can *carefully* take off a wiper blade from your vehicle, but these normally have metal back- pieces so only try this if your confident you won't scratch your car! Use a decent synthetic leather, again make sure this is clean and free from grit, you can do detail work such as door and boot sills. Leave your car to dry for about an hour, as residual water normally lurks on overhangs and can ruin the polishing process. Don't spend loads of money on polishing cloths, complete waste of money. Just get a dedicated "put- on" cloth, and a smoother "take off" cloth. I also like to polish my alloys as it makes them easier to clean in the future.
My other strong piece of advice is not to clean your car on a hot or sunny day, especially if it's a black or dark blue car. Doing it in these conditions will make the job twice as hard and lead to a poorer quality finish.
My recommendation of where to spend your money is on a decent polish. Autoglym is used in the trade and gives a great finish, but there are many similar products selling for less which give an almost as good finish.
Hope that helps.
