There are many tricks to applying for jobs. I have also walked door to door and asked for jobs and the 6th place I applied at hired me on the spot and I worked there for over 5 years. Once you get your foot in the door and start working somewhere, you will start making connections. Even if you stay at the same company, other people will come and go and if you make a point of keeping in touch, if you lose your job, you can put out the feelers for a new one among all your old co-workers who have moved on and are working somewhere else.
A very important point is to dress appropriately. If you are not sure what is appropriate for the workplace you are applying at, you should go on a scouting mission before you go for your interview and look at what their other employees are wearing and then show up looking like you fit in. If you are applying for a blue collar job, show up clean but wearing working clothes so if needed, you could start right away. They will probably not ask you to do that but they may ask you to start the next morning.
Another important thing, especially when you are applying for high end jobs is to look sharp. I remember having seen a newspaper article about a 3rd world immigrant who in spite of being well educated and having worked in the UK for some years just could not find a job. What I noticed immediately about him is that he did not look sharp. His clothes and haircut looked terribly out of date and for that guy, I think it worked against him. So maybe that is not fair but life isn't fair either. If a boss looked at that guy and saw that he looks terribly out of date for Canada, he may think his skills are also out of date or that they are not relevant to Canada in any case.
Another thing is, if you need a survival job and can't find one, the reason is often that you are over qualified. Make more than one version of your CV and take the one with you that you feel is appropriate for the occasion. Applying for high end jobs, you would make more of the relevant experience jobs you have had and skip odd jobs you have done during your university years while applying for low end jobs, you might rearrange your CV to stated that you studied at a university without mentioning that you graduated, that you worked at such and such company but minimizing your job duties there, to list all your odd jobs you ever did during your university years etc.
And if you end up seemingly stuck in a survival job without having any luck in finding something relevant to your education, you should think about re-training, either in your old field or a new one.