We found a good way to do it, and keept to it every time. What we did was
1: Tie the head to the halyard (Mark the head)
2: follow the luff tape down to the tack, tie the tack to the tack line
3: follow the foot tape back to the clew, tie in the sheet
4: Thread and tie the retrieval line
5: Hoist the spi partially to check it and snuff it

Threading the retrieval line was the only thing we needed to be careful about. Easy to mess it up, so doing exactly the same way every time is good. Marking Clew, tack, head and the luff tapes if they are not color coded is good.