Feathering needs practice, let your finger hover over the spool during the cast, just so you can feel the line slapping your finger. Just as the lead is about to hit the surface of the water, trap the line to the spool, using your finger and gently lift the rod as the rig sinks. When you feel a donk, you have hit bottom.
All your trying to do is throw the rig out in front by trapping the line with your finger. Lifting the rod during descent will hopefully keep the whole rig straightened out.
If your paranoid that this hasn't worked try two foam nuggets and drag the rig back towards yourself when you feel the donk.
It made sense in my head, sorry if it doesn't in yours lol
