This method is obsoleted by the LJA method discovered by Rachel74, listed below. It was not deemed faster to skip the messengers when this was discovered in 2009, due to the route needing the rupees from the treetops. This was the first method discovered and is listed here for archival purposes.
This trick is also commonly referred to as 'Blind Snowboarding' due to the fact that the fog effect never disappears while you're snowboarding. By Voiding out far enough down towards the snowboarding track the game will spawn you as if you just failed snowboarding which is within yeto's text trigger and hence skips the Snowpeak Portal.
You can do this on either side but is easier and faster on the right side. Roll to the corner of land shown in the video as that is as close to the edge you can be without trigger the Portal CS, then LJA along side the wall and you will bypass the warp point. If you are slow at aiming the kesee might try and attack you, in which case step back away from the portal trigger and then slash them, if you spin attack you will move forward and most likely into the portal trigger.
It saves 24 seconds to skip the portal however it should be noted that the rupees on the tree-tops don't spawn and so rupees will need to be collected somewhere else. It is also important to know that you will not be able to see because the fog effect never goes away until you beat the portal so you will need to remember the turns of the shortcut.
This trick can also be performed without a Gale LJA by rounding up Keese in the Gale Boomerang, and jumping attacking towards them when they come back in range after throwing them over the void towards the wall.
It saves 10-15 seconds to skip the portal this way, but notably different from Gamecube, the rupees and keese remain loaded in the Wii version during snowboarding.
This is currently used in the 100% route and saves around 5 seconds done well. The idea behind this trick is to enable Map Glitch so you don't void out and to the LJA across the bottom of the map towards Snowpeak Ruins From the beginning of snowboarding, once under the bridge you hit a trigger so when you savewarp you will spawn outside Snowpeak Ruins. For this trigger to exist you need to have hit the midna text before Snowpeak Ruins first, however 100% splits Snowpeak Ruins into two trips so it can be done the second time coming.
1) Enable Map Glitch
2) Climb Up Right Next To The Tree As Shown In Video
3) Sidehop Right Twice (If You Mash You Will Sideroll After The First Sidehop)
4) Aim at the White Spot Just To The Right Of the Peak Of The Left Mountain
5) Reaim The Boomerang So It Isn't Thrown Down
6) Once Thrown LJA As Soon As Possible So You Don't Loss The Angle
7) Savewarp Once Under The Bridge
This is used to be for 100% because it allows you to save movement getting the poe on the first trip down the mountain. Although the wolf is slower than snowboarding it does skip cutscenes and hence a little faster. To do this you must LJA over the first gap, the only way to LJA in the deep snow is to not move at all after transforming into human, if you move you can't jump attack. All the other jumps can be made as wolf, for the first jump in the shortcut you can use the rock to the left as a bridging point. The second jump in the shortcut is a little close but if you make sure you dash just before the edge you will have full speed and be able to make it. Finally you can LJA over to the poe mountain as shown in the video.