Split jerks are coming up next week during the strength portion of a class. Here are 5 things to think about and work on in preparation for that movement.
1. Stay on your heels during the dip.
2. Dip straight down and drive straight up.
3. Think about pushing up on the bar in an effort to drive your body down into the receiving position.
4. When you recover from the lift, step back with your front foot then forward with your back foot.
5. Have fun.
Also, use the simple diagram above (from CrossFit Invictus) as a general frame of reference to get your feet into the correct position to receive the lift. Practice this as a part of your warm up with no bar or a PVC. Also, get in the habit of videoing your lifts so you can get some visual feedback on how you are moving.
Finally, here is an article from the CrossFit Journal if you would like some more detail on how to properly execute this lift.