Australia has a fairly sensible system. We cannot turn boats around in the way they can for obvious reasons (geography, origin of migrants, size of boat involved etc) but they remove all migrants arriving without prior agreement/ visa/ papers to remote processing centres on separate islands. The UK has many such uninhabited island territories. There is also a law that nobody arriving by illegal methods without a visa will ever be granted entry to Australia to live or even visit as a tourist. Such rules make attempting to enter without prior arrangement far less attractive.
They take a quota which they determine per year who arrive with permission (around 20k per year I think) and thoroughly background check them first, check criminal records, check basis for asylum claims to ensure these are people in genuine need, then allow those granted asylum via the quota to come to Australia after their claim is granted, by normal means of transport, and they can then integrate and work immediately with accommodation/ employment having been arranged in advance rather than them being a drain on resources and contributing nothing for years. This is also far better for the refugees.
It also means they know who the people are so if they subsequently break the law they can be deported to their country of origin far more easily. The granting of a place can be made conditional upon taking up work set up for them in advance in occupations that the UK requires according to their level of skill so there is a clear expectation that they contribute and it can be made clear in advance what is expected regarding compliance with our cultural norms and laws.
As a result, people trying to enter Australia without a visa or pre-approved asylum having been granted is now rare.
Denmark has sensible policies in place now: limiting asylum claims which are granted to 2-3 years and then reviewing periodically whether their home countries/ areas are now safe for them to be returned. Refugee status is temporary and is not a route to permanent residence/ citizenship.
They also have strict criteria for family reunification: if you wish to bring other family members at a later date you must show you are able to support them financially, provide housing for them etc, that you have stable employment and have passed language competency tests. You have to show you have been self-sustaining and not accessing any kind of welfare for several years before this will be considered.
Since such a low percentage of refugees in the UK (with claims granted) work (or at least, not in legal employment paying tax) let alone are self-sustaining this would prevent most from subsequently applying to bring here to join them multiple family members who speak no English and have zero work prospects and no intention of integrating.
One of the big pulls to the UK and why so many men arrive alone is because they can then bring extended family later. If we imposed rules like the above the incentive to come here would be far lower because the chances would be very low of most of those arriving currently being able to meet the criteria for family reunification i.e. demonstrate sufficient earnings to support extended family members as well as themselves and the employment record and language competency required to meet these criteria.
This would also discourage black market working because if working in the black market they could never demonstrate their income to meet the criteria to bring family to the UK, and it would also encourage those genuinely trying to build a new life here to work hard, pay tax and integrate. Plus, we need ID cards to stamp out black market working in general.
While the plight of many around the world is terrible, there is obviously a limit to how many people the UK can sustain so sensible measures have to be taken to make coming here without permission far less attractive, and to provide a sensible way to integrate a smaller number coming here with permission in advance, ensuring these are people with genuine claims and who are not violent/ criminal and do actually intend to integrate and work to provide for themselves.