These are sweet and juicy tips that ME AND MY BROTHER discovered. They involve getting things really early.

[1]. Biggoron's Sword

Did you know that you can have the Biggoron's Sword before the Forest Temple? It only requires the will to do so...and Epona. If you don't know how to get Epona, then I suggest you ask for help on it. But to start the trading sequence, go to Kakariko village(all of trading sequence is as adult). Talk to the Cucco girl near the path to the graveyard. She will give you a Pocket Cucco, her own invention. She probably just stuck a Cucco in a washing machine. But anyhoo, go to the house near the stairs near the well. Inside is poor Talon, who was kicked out of Lon Lon Ranch. He sleeps away to lay off the depression. Wake the poor guy up by using the Pocket Cucco. He won't be too happy. But the Pocket Cucco is. Show it to the Cucco girl to recieve Cojiro, a rare blue Cucco, who hasn't crowed since the Cucco girl's brother left. Maybe it will crow if it saw him again. He is wilting away in the Lost Woods. Enter the Woods and go left. He is over near the large stump thing. Hand Cojiro to him to get the Odd Mushroom. But beware. You're timed for this next one! Head back to Kakariko village. Enter the new potion shop, which is near the gate to Death Mountain. Head through the back door in there. Climb up the stairs and open the door. Talk to the lady. Show her the Odd Mushroom. She will give you the Odd Potion, a medicine for the weird looking guy, who actually is her son I think. Pretty sure. But when you reach the area where the guy was, a Kokiri will be in his place. Show HER the potion. She will blab on about Stalfos. Who knows what she means? But you will get the Poacher's Saw. Head to Gerudo Valley, which is a little ways away from Lake Hylia. Jump the gap with Epona, or use the Hookshot to latch on to the support. Either way is nice. Show the Poacher's Saw to the angry man there. He will thank you and give you a major item...THE BROKEN GORON SWORD. Head to the top of Death Mountain. Hmm. Nothing here but a Great Fairy Fountain and the path to the Death Mountain Crater. But what's this? A rather funny looking hill is over on the right. Why don't you approach it? I nearly fainted when I saw this. Ladies and gentlemen, I present to you...BIG-GORON. That's Biggoron. Funny ain't it? Anyhoo, you'll notice he's rubbing his eyes violently. Show him the Broken Goron Sword. He will offer to fix it, but he says his eyes are really irritated from that eruption yesteday. Riiiiiiight. I mean, his head goes up to the tippy top of the mountain! Anyhoo, he will give you the Prescription for King Zora. But unfortunately...King Zora and the Zoras have their own problems. Yep. They're frozen. Head to the Zora Domain. Go behind King Zora to the Zora Fountain. Jump across the ice blocks until you reach the mini-dungeon, the Ice Cave. Go in this mini-dungeon until you manage to grab some Blue Fire with your bottle(s). Leave the cavern if you wish, but if you want to make things weird, go further until you obtain the Iron Boots. But anyhoo, unfreeze King Zora with the Blue Fire. He will give you a Zora Tunic as thanks if you just talk to him. Zora Tunic before Forest Temple? Whoopee! But show him the Prescription. He will give you the ingredient, the Eyeball Frog. Funny, those aren't big eyeballs. But anyhoo, ride Epona as quickly as possible to Lake Hylia. Go inside the lakeside laboratory and show the Frog to the old man. I did this with 2 seconds left on timer first time. He will start to cook it, but you tell him it's for eyedrops. He agrees to help and spends 7 or so seconds working. Now is a fairly tricky part...You have to take the eyedrops to Biggoron in 4 minutes! Whoo! If you are good with Epona, and easily scale the final wall on Death Mountain with the Wall Skulltulas, then you could have 40 or so seconds left. Give the drops to Biggoron. BOOYAH! The Biggoron's Sword is yours! Before the Forest Temple! W00T!

[2]. Zora and Goron Tunic before Forest Temple

Yep. It's possible. Easily actually. For the Goron Tunic, head to Goron City. A lone Goron will be rolling. Carefully time a throw with a Bomb Flower to hit him. If successful, he will stop. What the?! His name is {your name}! Ah. Darunia is his father, naming him after you, the Dodongo Basher and Hero. Ask him about the Dragon and Gorons to get the Goron Tunic.

For the Zora Tunic, merely take some Blue Fire in the Ice Cave(see above in Biggoron's Sword) and unfreeze the King of Zoras. Not too hard.

I think it may be possible to do the first 3 dungeons in any order as you wish. That's the Forest, Fire, and Water Temples. If you have any info on this, please tell me. NOTE: You will need the Hookshot for all these dungeons. Basically.

Long isn't this?