One-and-a-half mount suicide.
Challenging but manageable trick for the early/intermediate player. If you're trying to get your one-and-a-half mount consistent, this can be great motivation.
If you need more help with the mount, a good tutorial can be found here in the lessons section.
Remember that when you land the mount, the lower your yo-yo hangs, the bigger the loop when you throw it. If you pull it up too high while it's cradled in the mount it will make a smaller loop and will be much harder to catch.
When catching the loop, be sure your loop isn't twisted before dismounting the trapeze. If it is, just twist around your finger until it's straight.