During Devil Trigger with Dante, you can infinitely use Trickster style's ground Dash.
A useful method to deal massive damage to an enemy or boss with Dante is to equip Lucifer, switch on Devil Trigger and spam Pin-Up, the resulting damage is massive, even in Dante must Die mode.
A more widely know "secret" is related to Dante's Gilgamesh weapon attack, Real Impact, it involves executing Real Impact out of Devil Trigger, then when Dante connects with the first hit, engage Devil Trigger and then wait until roughly the third hit to strike, this is when you turn off DT, this gets you a huge power spike while still getting all five hits of Real Impact with the power of Devil Trigger, this technique is known as Distorted Real Impact, this may not be 100% correct, but it's roughly how it's done.
A decent and very simple combo for dishing out a good amount of non-stop damage involves the use of Yamato and Rebellion in Darkslayer style, it simply involves attacking with Rebellion twice, then Yamato twice, useful tactic for Dante with bosses who are stunned, and you have no access to Devil Trigger.
Another fairly commonly known ability is with Nero, during the Devil Trigger Buster scenes on stunned bosses, providing you have shot at them beforehand, during the Buster sequence you can repeatedly tap the shoot button to fire Summoned Sword at the boss during the Buster, this allows for a nice addition of extra damage on top of the Buster attack.
Another ability relating to the Buster is, during a Buster sequence with a boss, tapping the Buster button repeatedly seems to increase the damage output, this also works on regular enemies, increasing the length of the Buster sequence and doing more damage.