Using the Volt Driver on Cretaphids, other Hunters, and Guardians is rape, it takes them out incredibly quickly. If the Guardian has a Volt Driver though, use the Battlehammer.
In Incubation Vaults 01 and 02, you can use the tank in the room to make a tricky jump back up to the second floor. I'll get video of it later.
In Ice Hive, after getting the third artifact then going through the tunnel to get to the portal that leads to the Hunter Gunship, you can use the Ice near the wall to jump up to the Portal to the Boss.
In Incubation Vaults 01 and 02, you can use the tank in the room to make a tricky jump back up to the second floor. I'll get video of it later.
In Ice Hive, after getting the third artifact then going through the tunnel to get to the portal that leads to the Hunter Gunship, you can use the Ice near the wall to jump up to the Portal to the Boss.