Remove from play, from your side of the field or your Graveyard, Fusion Material Monsters that are listed on a Dragon-Type Fusion Monster Card, and Special Summon that Fusion Monster from your Extra Deck. (This Special Summon is treated as a Fusion Summon.)
Since Dragon's Mirror can be used on most Dragon-type fusion monsters, it can be viable in different dragon decks. Five-Headed Dragon is automatically added to the deck if you are using the skill, and it can be fusion summoned using any 5 Dragon monsters. This can give some flexibility if you are using any Dragon type deck.
Dragon Knight of Creation and Paladin of Felgrand can be good ways to get Dragon-type monsters from your deck to the graveyard. This will thin your deck and help with drawing Dragon's Mirror, as well as setting up for fusion summon later by using them from the graveyard. If you are using some normal Dragon-type monsters, you can use Hieratic Dragon of Nuit to also get them from your deck.
I just got the entire Dragonic Knights starter deck, Chazz and his skill, and everything. I was wondering if there was an easier way to get Dragon's Mirror from my deck. Is there a card or something that can help me fish it out of my deck?
I tried that once in a duel, but it didn't work... I ended up losing because I ran out of cards in my deck. So, I dropped back down to one Magical Merchant, but I got rid of multiple copies and unnecessary cards from my deck. My deck improved dramatically with 7 spells/traps, only one Paladin of Felgrand, and I don't even use the Guardian of Felgrand anymore!
It's not like you're removing from play monsters from your field. They can be in your graveyard, which is a plus IMO. Say you're getting your ass handed to you, with your opponent destroying your monsters, you can use this to summon Five Headed Dragon. You're just banishing monsters so you have nothing to lose.