Having a plan when it comes to engaging the wind. When you are on the firing line is not the time to calculate long hand math formulas to figure out the wind call.
Have a plan before you hit the range, make sure you know what your wind holds and values are before you need to shoot. Too many focus on the wind in terms of trying to use the formulas available. The time to use the formulas is before you leave the house. A little prior proper planning goes a long when it comes to engaging targets, both on the range and in the field. Using a chart like this much easier than doing long hand math
All the formulas are correct to a point. Make sure you are using the correct constant in terms of your bullet. Constants used in these formulas are based on a specific round. In order to figure the correct constant for your rifle you have to work the solution backwards. See the image below
As you can see you need the actual hold used to find the correct constant. So it's not something you can do without knowing your actual hold unless you use a computer. Software will give you the correction, however if you are software you can get an accurate wind chart from that and you have need for the long hand math. Today, it's not worth doing the long hand math when computers are so much more efficient.
This example was taken from JBM Online, a free ballistic application that is very easy and accurate to use. If you feed it the correct information, the end results will be well within 1 MOA of your target.