Be realistic with your timeframe; begin actively looking for a rental property at no earlier than three months prior to the date you can actually move. If you begin to look any earlier you are unlikely to be able to secure a property as a vendor will prefer an earlier move in date. A standard time frame of an offer being made and actual move in date can be anything from two-six weeks.
Understand your housing license and restrictions.
Be clear in your requirements and understand what is a "must have" and what is a "wish list". Think about parishes, schools, budget, bedrooms, parking etc. and inform your agent of this so that they can narrow down suitable properties.
Give honest feedback during your viewing so the agent will have more of an understanding of what will and will not work for you.
Be clear with your offer and include the amount, date and term that you wish to take the property for and be sure to tell the agent if you have any specific clauses you wish to have included in the lease or if you wish to make any changes to the property.
If your offer is accepted, arrange to have the deposit transferred within a matter of days and provide the agent with the documentation they have requested for references. The sooner you provide this, the sooner the lease can be signed and the property secured.
Please note that until the lease is signed the property has not been secured and can still fall through. If a property is for rent with multiple agencies the vendor can continue to allow other viewings to go ahead including sales viewings if it is for rent and sale.
Most importantly ask questions both at the viewing and with regards to the rental process. Once you have signed a lease on a property you are committed to a legally-binding contract.