I am a UPS driver and leaving a note will not do the trick. The shipper pays us to make sure that we get a signature from someone at the residence with a valid ID. We are also prompted in our DIAD's (hand held delivery information acquisition device) that we must get a signature from someone 21+. In order to complete the stop, a signature MUST be made. If no one is home, and we sign FOR you, we become liable for that package, not to mention I could be fired for doing so. Generally speaking, I would only ask for ID if the person appeared to be around 21. Aside from that I may flatter the missus' of the house if she is in fact a MILF.
If someone cannot be home to sign for it, your best bet would be to call the local UPS hub and have them hold the package for pick up. If you would like it delivered somehow, I would suggest calling the number on the Delivery Notice and try to have the package re-routed to your place of business. After 3 delivery attempts have been made, the package will be held at the local UPS hub for 5 days before it is returned to the shipper.
Personally, for a more hassle-free experience I would call and have them hold it for pick up. Less variables to go wrong.
There are some driver's that will falsify documents by signing for you and leaving the package out of laziness and not having to return the next day, but they run the risk of getting fired. So there are some people that will have the experience that a nice note, or "leave it with a neighbor" may work.
However, with an Over 21 Signature-required package, we are required to get such and not from the neighbor, but an actual resident of the home.