For both characters:
1. Make good use of Side Roll.
2. Do not be ashamed to use items when playing DMD Mode, because it was really tough. This includes DMC1 and DMC3, where sometimes I have to rely on items, like Vital Star.
3. Eliminate your enemies quickly before they start using Devil Trigger, especially bosses, Blitz, Frosts, and Mega Scarecrows. Other enemies can be a threat when they are in Devil Trigger as well.
4. Make good use of Air Hike, as it allows Nero and Dante to jump twice in the air, avoiding any attacks from the ground. Take note that when Dante is in Devil Trigger, he can use two Air Hikes.
5. Use Holy Stars ONLY when you are near death, surrounded by multiple and tough enemies, fighting bosses or if you have a lot of it. But it is advisable to use it sparingly, since it is really expensive.
6. Learn your enemies patterns and moves. Learning on how they attack and moves can prove to be useful, as you can immediately dodge the attacks without any damage if you are good at reading the enemies moves.
7. Use Devil Trigger when your enemies are in Devil Trigger, or when in emergency.
Nero
1. Do not rely too much with your Blue Rose normal shots. Instead, use Charge Shots, Level 1, 2 and 3 are good choices, but the higher the level, the longer the charging time is.
2. Practice to use Exceed before you enter a new area. This way, you will get first advantage by attacking your enemies with powerful Exceed attacks.
3. Make good use of Nero's D.T Explosion. It allows you to be knock the enemies to the air, giving you some time to attack or escape.
4. Rely on your Buster moves to kill enemies quickly. Whenever the bosses are vulnerable to Buster, do not hesitate to use it. If you have enough D.T., use Devil Buster.
5. Use Snatch to get close to your enemies and pummel them mercilessly with your Red Queen and Buster.
Dante
1. Rely on Rebellion and Dark Slayer to defeat your enemies. However, your playing style is varied, so it is up to you.
2. Dante's D.T. form allows significant boost not only to his strength and endurance, but it allows Dante to have some added bonus in his moves. Dante can use infinite times of Dash, can do double Air Hikes, and other moves.
3. Depending on your playstyle, make sure you use Styles appropriately.
4. Dante's Swordmaster moves can deal high damage, especially the Drive techniques.
5. Dante's Pandora can defeat any weak enemies easily, so make good use of it.