When planning a formal event, frequently problems arise which for the most part can be avoided or simply resolved if a few simple rules are adhered to from the outset.

1. Always ask for an estimate and if possible ensure that it is in writing.  Always ask what is included in the cost (particularly, if it is given on a per head basis), as what may seem reasonable from the outset may be far more expensive once all the hidden costs are exposed.
2. If a verbal estimate is given and accepted always follow this up with an email or fax to the company or individual concerned confirming the estimate, accepting it and placing the order. 
3. Most venues and other services require a deposit to be paid to secure the booking.  Always ensure that you are given a receipt and also ensure when you come to pay the final balance that the deposit is deducted. 
4. Many venues allow you to “pencil in” a date without payment of a deposit.   This can be risky as you have not secured the date and frequently this is when double bookings may arise.  If you want to book that particular date, pay the deposit and secure the booking.
5. It is important to consider the full cost of the event from the outset.  Make a realistic budget and stick to it, otherwise costs can mount up quickly and in some cases spiral out of control. 

The lead up to a formal event can be extremely stressful.   However, if you have all costs itemised and in writing, problems can be far easier resolved, than would otherwise be the case.