Ok this is just an attempt to come up with some kind of list of grabs with directions on how to do them, then throw some pics in to make it easy for everyone to understand. I had noticed a lot of "I need new grab" threads and figured this would be a good start to them. All the pics are going to be off of NS and be cited to their rightful poster. So wish me luck, and lets get started
Safety Grab
Probably the easiest grab to throw. Simply take your right hand and grab under you're right binding on the outside of the ski. While this should be outrageously self-explanatory, here is a pic can be doubled by grabbing with both hands.
(pic courtesy of member Phisherman)
Next up is the Mute grab. This is done by crossing the skis, and using the right hand to grab the outside of edge of the left ski in front of the binding. Balance is often obtained by raising the left hand above the head. Not overly difficult and still very stylish. This pic shows the grab very well but with the hands switched.
(pic courtesy willyy)
The Japan grab is done by reaching your right hand behind your back and grabbing the inside edge of the left ski at or behind the tailpiece.
(photo courtesy of TheRich)
Critical grabs are very similar to japan grabs, except instead of being grabbed behind the binding, you grab in front of the binding. So you reach across your body, grab the inside of edge of the left ski with right hand, in front of toe piece. Look at the third and fourth step for best shot
(photo courtesy of Freestyla981)
Toxic grabs are done by crossing the fronts of the skis, then grabbing the inside edge of the right ski with the right hand.
(photo courtesy of leviormsbi_y86)
True tail grab is done by crossing the front of the skis. Then grabbing the very tip of the tail of the right ski with the right hand.
(photo courtesy of dahroots)
Blunt grabs are grabbing the outside edge of the right ski with the right hand, but with the skis uncrossed
(photo courtesy of max-dog)
True nose is the right hand grabbing the outside edge of the right ski at the tip.
(photo courtesy of dahroots)
Crouton is grabbing japan with the right hand then grabbing the inside edge of the left ski with the left hand.
(photo courtesy of AndrewZ)
Truck driver is done by having both right and left hands grabbing outside edge of the same ski (right to right, left to left) arms fully outstretched, in front of toe piece
(simon dumont, courtesy of tellurideknight)
The octograb is done by crossing skis then grabbing nose on the left ski with right hand and tail on the right ski with left hand. Or vice versa (See Gagnier during the Xgames '08)
(photo courtesy of reippailija)
Ok so these are the basics without getting into double grabs and such. Feel free to add something to the list, just search the media and find a good pic to go with it.