"Tuning" is a spell that adds one "Synchron" monster from your deck to your hand.
"Reinforcement of the Army" can be used to add a level 4 or lower warrior-type monster from your deck to your hand, which can also be used for warrior-type tuner monsters.
"Key Mouse", if destroyed by battle, can add "X-Saber Airbellum" from your deck to your hand.
"Sangan", if sent to the graveyard, can add any monster with 1500 or less attack from your deck to your hand, including tuners.
"Goblin Zombie", if sent from the field to the graveyard, can add "Plaguespreader Zombie" from your deck to your hand.
"Drill Warrior" can add any monster from your graveyard to your hand, when he returns to the field with his effect.
"Monster Reincarnation" can put a tuner from your grave back into your hand.
So really, it depends on what kind of deck you're running, and which tuners you want to use. These are just the examples I know of, off the top of my head.
Chat with our AI personalities
You can, only if something specifically says you can. Tribute for most Ritual Spell Cards can come from hand. But if the card doesn't specify, the tribute must come from your side of the field.
Dark Magician of Chaos and Magician of Faith both had this power, but they are currently both Banned. The only legal card I can think of off the top of my head would be Magical Stone Excavation. Also Z-One
There is no real hard limit - as long as you've got a spell card in hand, and a slot in the S/T zone for it to go, then you can activate it.
take a real yugioh card, then look in the bottom left hand corner, take the code and enter it on the game.
One of them for sure is Lightning Vortex.