This Glitch is very simple but very usefull!
Can be used in - Dungeons(CM)(Timewalking)/BG and the world.
Use trinket: Barov Lumberjack Caller
Unlike other Summoning trinkets this trinket lets you keep the 5 lvl 100 Guardians to fight for you for 10 minutes EVEN AFTER unequiping the trinket, so 10 minutes per hour you got some free extra dps! and Trash on enemy screens.
It can be obtained via the quest: Reduction in Force
Which is a Lumbermill quest from the Garrison.
This is pretty big imo, since you can even use it in CM. They hit every 2 sec and hit for 1 to 2k, so that's about 10k+ dps for 10 minutes, or untill they die.
Which is huge in CM's.
Have fun with it!