The easiest way is to be abroad and not register, like me. The best reason is that registered at my mother's address in Toronto's outer suburbia, there is no way for me to influence the vote. My mother's address is in the Ontario '905', which always overwhelmingly votes Conservative. I certainly don't. Let me give you an idea of what I mean. There are two key demographics in her town: the townies who have been there forever, and are the Canadian equivalent of 'Tea-Partiers'; and the people who have moved there from suburbs closer to Toronto, that had become 'too brown'. Charming bunch both of them.
Nobody has a problem with my Asian wife, nor the Conservative incumbent: but Asians are honourary whites, right? I could ignore the fact that at the last event I went to at the fair grounds only three people were not white, among hundreds: and one was my wife. However, there is the story that my mother's neighbour told us: a real-estate agent tried to sell him a different house in town as there were not many 'of those people' in town. He challenged her with the fact that he'd had no problem living with 'those people' for two decades in Kenya. In addition, an entrepreneur had his shop repeatedly broken into, and was once beaten by townies. Why? Was it more because he is SE Asian, or because his manners were effeminate (he has a wife and children, not that his sexuality should matter). He closed his shop and left. This is Canada outside of the cities, never mind the propaganda of 'multiculturalism'.
If you are thinking in American political colours, you have it backwards for Canada. Blue is 'Conservative': which is politically correspondent to Republican. Red is 'Liberal' (we dare use that word): which is the left wing of the 'Democrats'. Orange is 'The New Democratic Party': which is about where the Naderites are on the spectrum, but such is mainstream in Canada. Turquoise is the 'Bloc Québécois': which is an ostensibly separatist regional party, and socially where 'The New Democratic Party' is.
There has been a lot of change in the political parties in Canada in my forty years. Canada is, like the US, split between those who identify themselves as 'moderate' or 'progressive' and are mostly urban, and those who identify themselves as 'conservative' and are mostly suburban. The rural areas are split regionally, where some regions are 'progressive', and others are 'conservative'. This is complicated by Quebec, which votes for socially 'progressive' representatives, for the most part, but who have their own 'progressive' quasi-separatist federal and provincial parties (quasi-separatist, because there are not enough 'pure-laine' and separatist Québécois to achieve separation in a vote: tried and failed twice, already).
In short, the middle and the left are split, and the right is in the 'Conservative' party: who even so cannot achieve a majority. We do have two houses, and an official head of state, but in essence it is only the race for the House of Commons that matters in the Dominion of Canada. There is such disgust with the 'Conservatives' that many Canadians will vote for any party in their riding which can defeat the 'Conservatives'. This has not always been so, but the longer their sociopathic and flat-affected leader has been the head of a minority government, the more this is true. Alas, the leaders of the other parties are too narcissistic to make an effective coalition, though there have been some poor attempts by others in the parties. The election is Monday, May 2nd. We will have either another 'Conservative' minority government, or a coalition led by 'The New Democratic Party'. The latter is unprecedented in Canadian federal politics: the 'Liberals' had been 'the natural governing party of Canada', but have squandered all of their good will. I will never vote for their leader, Michael Ignatieff', for the same reason I will not listen to Christopher Hitchens: 'liberal' apologists for the invasion of Iraq and American imperialism. Typical members of the courtier class.
There is a whole lot of ugly in the way the right/left gets split in Canada, and much of it is malignancy from American media: politics of race and of sexuality. It does not play quite the same as to the south, but our racial history is different (though not without sordidness), and the mainstream is more accepting of homosexuality (though not universally). 'The Conservatives' do not race-bait in the way that many 'Republicans' do, though policies against the poor amount to the same thing: just switch Black and Hispanic for Caribbean and Native in Canada. We have a mealy-mouthed national character, so nobody will say exactly who they want to scapegoat, but everybody knows. As for homosexuality: legal marriage and adoption to be sure, but just try living 'out' in the hinterlands. The 'Conservatives' have gone fishing for votes among the immigrant communities, as all the parties do, but have specifically targeted those ethnicities least tolerant of homosexuality and reproductive choice. How nice.
I do not believe in the vote, in the 'democratic' structure we have, but I would vote strategically as any option is better than the 'Conservatives'. Only my dissenting vote in my mother's riding is a drop in the sea, and pointless to make. A good friend suggests that my pointless vote would at least give a party that portion of the voting subsidy, but if there was a party I could enthusiastically support, I'd send them more than that $2.