Here is a solid pass demonstrated by Rener and Ryron Gracie. They do a great job of explaining the technique for both self defense and sport jiu jitsu.
This is a pretty basic pass but there are a few details that they go over that will make the difference. One of the things that I do a little different is to start with a Gable Grip when I go for the Underdog pass. This is important if your opponent drops their legs to make it difficult for you to lift them with your arms.
One of the details that I thought was on point was when they drop their head while doing the pass. This will protect you from taking any shots to the face. It is a small detail but could save you from getting cut on the face while doing this pass.
