Advise for first homebuyers in least affordable countries such as Australia, New Zealand and Ireland?

How do you advise first homebuyers to buy their first homes without overpaying for houses that they are hoping to buy?

Generally, first homebuyers lack knowledge and trend in the real estate market. In addition, they do not have knowledge about macro economic conditions, interest rate trend. In addition, they do not have any experience in real estate like experienced investors, speculators, traders and real estate agents.

Some new first homebuyers do not have knowledge to get better interest deals from the banks. In addition, they have overpaid for houses in these least affordable countries. Further, if they lose their jobs they will lose their houses as well. Unemployment is increasing gradually in many countries.

What precautions should they take when they buy their first homes?