I don't think this works so well for big airlines in Europe, but I got my first job (non jet) by getting to know the management of a small company. Scenarios like this will often be different depending on the person, company and location, but in this instance I did this by very very occasionally renting out one of the SEPs that the company owned. For an hour spent in the air I would spend at least the same (more if it was appropriate) hanging around the offices, getting to know the people and the operation, and I let them know early on that I held the appropriate qualifications to work for them if the situation ever arose. I did my mcc course a few months after finishing my MEIR and the day after I returned home I rang the GM of the company and told him I had completed my MCC (which wasn't even required by the company) and if they had any FO positions going I would be very interested. I was told that there was nothing available. A week later they called me back and said they had a position for me.
Once you get in somewhere like this it becomes much easier to network, because you end up interacting with far more people in the industry. I would speak with crews while hanging about airport lounges, I would speak to aircraft owners who were around the airport, when the local skydiving club ran their bowser down to us to buy avgas, I had a CV to give to them. I often had a CV or two in my flight bag and if we flew anywhere where an operator had an office, I would pop in and have a chat.
As I said this was how I got my first job, and I had built up a good prospect of more freelancing odd jobs (owner flights/paradropping/aircraft recovery) before I ended up getting an airline job through an online application with no contacts.
You need to have the willpower, put in the effort and have a good dose of luck.