Wind direction
Remember to let the birds help you to determine the wind direction if you are in a area where its difficult to find where the wind is blowing from.
Birds will usually always take off or land into the wind expecially larger birds like Geese. So if you´re heavy and not particurlarly interested in getting into settling with power, get some assist from the birds around you, check which way they are landing and taking off or if you have some cliffs nearby see on which side they are hanggliding.
It never fails and is easy to observe while flying.