I apllied to BOI recently and was approved. But they are back to the correct way of lending. I.e. a lotof strict checks. You will need to be permanent. If you are not permanent, you may be seen as a dependent which could lower the amount they'll offer in a joint mortgage.
You need to be in a permanent job (the irony of it in this day and age), display to the banks that you can actually save money, and if you have correctly paid off previously loans like car loans or something that will definitely help too.
If you don't have a regular savings account, I would set one up immediately and start saving a little more per month what you would intend your mortgage payments to be. I.e. if your mortgage could be 800 a month, start saving 1000.