if it's just a frame, i recommend wrapping it in bubblewrap, the ones with the big bubbles, and masking taping the whole thing, i got a frame from pickle that way, full bike, i'd not reccomend it.
There's been a couple of posts on here from folk who have just attached an address label to a bike. . no wrapping or anything.. Can't remember the courier name but it only cost £8 or something like that..
On your own head be it.
Go to a bike emporium get one of their boxes and use that.
Delivery drivers hate people you dont package sensibly,they have got little room so big square boxes are easier to judge the packing order with,so might find its put in last and gets removed several times in its journey as they stop to pick up and drop off at sorting offices.The more times it gets handled the more likely it is to be bumped against loading bars etc
Also leave any hand grips already cut into the box,these are invaluable for safe damage free handling.the driver knows whats in it and its unlikely he'll get or even try to nick something off it