Cutting government waste should be the first step, then you know how much you really need, & can tax at appropriate levels.
Wrong...
First step is to figure out what you want your government to do. Most countries know this already. Yes it changes over time, but the basics are known.
Second step is to cut as much waste as possible or/and prevent it. Most countries are doing this, but yes it is a battle like no other. Special interests... suck.
Third is to set tax rates accordingly so there is no deficit (or very little). Most countries have good tax rates that conform to the expenditure.. under normal economic climate. Problem now at the moment is of course it is not "normal economic climate" and hence the need to tweak the tax rates.
And then comes the important part.. to make sure that every citizen and company pays the taxes that they are suppose to.
It is the last step, that is seriously lacking in many countries and it only relates to companies and the wealthy in the UK and most other countries (this does not mean Greece). Why only corporations and the wealthy? Because average Joe who avoids to pay his taxes goes to jail... where as companies and the wealthy do not.
Fact is when a corporation like Starbucks has sales of 1.2 billion pounds (1.8 billion or so dollars) in a year, and pays next to no taxes because officially according to the accountants the UK operations of Starbucks is loss making... yea right.... what they did was move the profits across borders to Luxembourg by calling them administrative and get them taxed there, at a much much lower rate... for sales done in the UK.. pathetic! then you know you have a system that is unfair and catering to corporations. You are basically pushing the burden from corporations onto the poor and middle class from companies that could feed many hundreds of thousands if not million of people with their yearly profits.
And then you have the wealthy in the UK and around the world, being able to move around their money and assets to the best tax havens money can buy, and most of the earnings are done in places like the UK and US, but the taxes are paid elsewhere. There are so many tax avoidance scams going on that the tax man cant keep up and the only ones that can use these scams are the wealthy, because they have the money to pay accountants to first figure out these scams and then exploit them. Yes tax systems are holed like swiss cheese often and that is the fault of the politicians, but it does not change the fact that the wealthy often do not pay their fair share of the tax burden and THAT is a major problem.
Also to be back on topic, the UK is a rich man's tax haven... London have more billionaires living there full time than any other city on the planet.. they of course dont pay taxes, but hey they do buy very expensive homes and spend on luxuries!