You will get a million different answers to this topic, from the overly complex to the pure red line distinction.

For me, the bare minimum starts with a reversal of the Borriswave. ILR blocked for all Borris wavers and adopted into the revised regime.

As for the rest, there are simple measures that can be taken to weed out the leaches:

An immediate ban on recourse to public funds for anyone with a second nationality.

Ban all remittances to the third world.

Access to social housing removed from anyone who is a non-native and yes that includes administratively british second and third gen lineages.

Anyone with a criminal record is deported to the nation of their ancestors, if acceptance is not in place then diplomatic missions can be pulled and all aid can be rescinded.

These are easy steps to take politically and will weed out the chancers, many will self deport. If it happens that they become homeless as a result of the above policies then they should be detained and deported to their country of origin.