Buy a box in your lbs.
Take the wheels out. (depending on the box size u need only to take off the front one out)
Buy some poliestirene blocks (foam) or get some piece/s from some tv set box at home or something.
Cut a block that fit tight in the box, drop it inside of the box, the piece needs to be big enough to insert the fork blades in there, just do two little holes and press the fork in there, that will keep the front end and the mayority of the frame firm and tight. Use common sense. A detail, do not take the fork out off the frame ok? just put it backwards and press it over the polyestirene or foam block u got.
Regarding parts ok? Take the RD, chain, pedals and depeding of the size of the stem probalby iu want to take it out also. Put all the little stuff in a small box, and drop that box under the frame if u like. Use some tape to fix it firm to the bottom of the box.
The handlebar. Use some bubbles wrap or whatever u want so it wont damage the frame. Just put it over the top tube. and use some tape to make it tighter.
Regarding the frame and the bike it self, put some cartoon paper or bubble wrap thing around the chain stays, top tube, fork or any other place u want to protect, as i said before, use common sense.
Now u have the fork stays firm with foam, do the same with the upper part of the front end of the bike, around the headset, cut a piece and stick it there, as makes sense sort of mold it with a knife, what I usuallly do is the same as the fork. I cut foam block wide enough to fit tight in the box and then I press it between the front of the box and the headset. That will keep the box tight from inside out.
Do the same with the Top tube area, cut foam with the form of the top tube and wide enough to fit in the box. Will keep the frame from moving left and right.
Put some paper into the front wheel and drop it inside, it will fit fine, the idea is do not to scratch anything, right? use tape to keep the wheel from moving.
If u thing something will come off take it off and put it in the box with the other small parts.
Close the box really well, Done!
I have shipped to Japan, europe and South America that way, not a single problem besides taken me like 2 hours to pack the bike and like 4 hours for the other guy to get the darn box open
Good luck.