yeah, so all the good advice on jump building has been given but two very important points need to be stressed.
1) On a pow day, you must find hard snow to make the wall blocks. This either means digging down into the snowpack or searching around to find a patch that is wind blown or whatever. You can't build good walls outta powder- it doesn't stack vertically and it will collapse...
2) TAKE ALL APPROPRIATE AVALANCHE PRECAUTIONS!!! Many people don't think about avvies on a 50m kicker landing but often they are prime trigger point i.e. 35 degree slope on convexities(rollovers), cornices etc. You really can't ignore this danger- test the slope prior to hitting it and wear transceivers when you do hit it (and know how to use them. My friend Leo was buried for 45 mins when the landing slid on him (the kicker was 100m from the piste) and he wasn't wearing a beeper. We found him with probes and he was unconscious and hypothermic. If you don't believe it could happen to you, watch this vid- he wasn't wearing a beeper either... (1:50)
http://www.youtube.com/watch?v=3-2t0GlWosw
DON'T LET THAT BE YOU, K?
3) Have fun!