Rights and wrongs

People over the age of 18 who are resident in the UK have the right to vote if they are on the electoral register. This essentially is updated every couple of years by the local governments via a letter asking you to declare who is eligible to vote in your household. A fairly simple system which only really became open to abuse by Labours relaxation of the postal voting system. Given that we have a right to vote, conversely it should be taken as a given that we also have a right to refuse to vote or register to vote. Sadly though this right is about to be made quite expensive...
Telegraph.

People who fail to register to vote could face fines of up to £130 under government plans to stamp out fraud and encourage a greater turnout at elections.
The new system of individual electoral registration (IER) would see individuals sign up to cast their vote rather than the current system which relies on the head of a household filling in a form stating the number of voters in a property.
The Government has scrapped plans which would have made failing to register a criminal offence.
Mark Harper, the constitutional reform minister, on Wednesday said: “We didn’t think it appropriate to criminalise people who simply didn’t register to vote.
“We do think it is appropriate to create a civil penalty, akin to parking fine, for individuals who, after being required to make an application by a certain date, have failed to do so.’’
The fines were unveiled as part of the IER system the Government hopes will crack down on voter fraud.

You want to stamp out fraud? Get rid of the postal voting system for anyone without a doctors certificate, that would do it.
Other than that I'm afraid the only way to get more people to vote would be for political parties to actually offer people something that they want. rather than what the political parties think they want or need.
Hanging a lot of politicians might help too.