Generally the first goal will be to get Dragonmaid Changeover in your hand or grave
To do this you'll need either Chamber or Parlor on the field, if Parlor simply, bring her back to hand to grab Changeover from grave.
Then, if you're going first, you'll generally want Strahl out on the field for a negate and the special summon during their standby,
If going second, Strahl is still great, however, if House is on the field, your girls switch to their dragon forms at the start of battle, she will destroy opponents monsters on the field for each that switch, at the end of battle if they still have monsters and you switch back she can pop even more.
Guardragon Legacy is good after you fuse to bring your girls back out on the field for more swarming potential.
You can have one of your girls switch to a dragon then use Tinkhec to give it 2000 attack until the end of turn and then have another switch into the Tinkhec now in grave.
Send Off is good for either switching for the summon requirements or switching during their turn to activate Houses effect to destroy when one returns to hand
Good luck, they are extremely fun to use and you'd be surprised how many people forget they switch in battle!
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