Canadian employers like personal contact -- preferably face-to-face contact but, at a minimum, phone contact.
Yes, to be sure, you should turn your British CV into a Canadian resume.
But just typing up a resume is not enough.
Just submitting online applications is not enough.
You need to phone prospective employers while you're still in the UK.
Yes, even if it's against your instincts to make cold calls, you need to phone prospective employers while you're still in the UK.
There is one caveat about phoning. If you complete an online job application or respond to an advertisement for a job in a newspaper, you must follow the instructions on the company's website or in the newspaper. If the instructions state that you should not call, then do not phone. It will annoy the prospective employer if you go against explicit instructions. However, it is acceptable if your covering letter states that you will be in Fredericton (just by way of example) from August 7th to August 15th, and would be available for a meeting.
It also is not good enough to confine your contacts to recruitment agencies. They can help you if your occupation is in red hot demand in Canada. If you're in that situation, you can include recruitment agencies in the mix. But, even if you do contact them, you should contact potential employers directly as well. And, if your occupation is not in huge demand, you should focus the vast majority of your efforts on potential employers.
In most cases, you also need to do a recce trip to Canada and meet prospective employers in person.
Networking is critical to the success of your job hunting efforts in Canada.
Please note that this article is addressed primarily to the person looking for work in the private sector, where there is a large hidden job market.
The public sector's hiring practices tend to be more transparent. Vacancies tend to be posted publicly, hiring decisions are more likely to be made by committees, and so on. Word-of-mouth is useful in the public sector too, but not to the same extent that it is in the private sector.