Adjust the car to the driving conditions.
This will prevent unwanted issues, and will save you time and money. If you're unsure, ask regarding driving conditions for your destination – you can ask the rental company, people you know or search on the internet.
If you are returning the car to an airport, remember to leave enough time to check in to your flight.
This is especially important during high season when there are many people and long lines. In most cases, it is recommended to get insurance which can save you money in the long run. However, you should not get insurance which is irrelevant to you, such as insurance for young drivers which costs more in certain companies.