We need to fully fund the Border patrols and allow them to do their job.
We need to reform welfare, I argue that not only is it being abused by illegals, but by the native-born as well, and it abuses me along with anyone else forced to pay for people not to work.
We need to prosecute companies hiring illegal workers.
We need to challenge the current interpretation of the 14th Amendment which allows a woman to walk across the border and give birth to an American citizen.
All of that, along with turning back the greatest number possible at the borders (100% would be acceptable), and deporting legal immigrants convicted of felonies AFTER they serve their sentences.
Now, I don't know if Mexico receives any sort of foreign aid from the US, if they do, stop it, and route the funds to be used to secure our borders.
These are just my ideas, there remains the problem of the existing illegals in the country.