I love knee cut passing, as it is a fast and explosive movement, which typically is my passing style. While knee shields are a popular way of blocking a knee shield, some opponents will try to block your hip with their foot.
This is quite simple to overcome, but we can go one step further and take their ankle. I used this back in 2011 to win my opening match against Cameron Rowe at the ADCC 2011 World Championships. The match was 0-0 and heading into overtime, so I was working hard to score or finish.