With a one in ten success rate, pretty hard actually.

These tips will improve your odds:

1 Resolve to make a change that you want. Success is more likely when driven by internal, rather than external forces.
2 Focus on one thing. Scientists have shown that willpower requires energy. Channel it well.
3 Be specific about what you want to achieve, when and how. You’re more likely to succeed than if starting with a vague plan.
4 Tell those around you. In a study, more than 70% who sent weekly updates on their goal to a friend reported success (compared to 35% of those striving alone).

The December issue features a cracker of a Miscellany Christmas special (page 99), packed with puzzles, games, bad jokes, amazing facts and forgotten wisdom, including: