Here is a little drill I like to use to loosen up. It can be started on any fret you like.
For instance, play everything in the first column with the index finger, second column with your ?2? finger, third column is the ring finger, and fourth column is the pinky.
Play the sequence in number order.
Just follow the pattern to the end and you will get the idea.
Use the standard down, up, down, up, as you alternate pick this.
---1----2-----4-----7-------
---3----5-----8-----11------
---6----9-----12----15-------
--10----13----16----19------
--14----17----20----22------
--18----21----23----24-------
Another inversion
---7------4-------2------1-----
---11-----8-------5------3----
---15-----12------9------6-----
---19-----16-----13-----10---
---22-----20-----17-----14---
---24-----23-----21-----18---
Now starting on the opposite corners.
--18------21------23------24---
--14------17------20------22---
--10------13------16------19---
---6-------9------12------15----
---3-------5-------8------11---
---1-------2-------4-------7----
And the last pattern
--24------23------21------18---
--22------20------17------14---
--19------16------13------10---
--15------12------9--------6----
--11-------8------5--------3---
--7--------4------2--------1----
After you master this, you might notice that JG uses small portions of these patterns in transitions and space.

