25 votes so far...
Lather - 9 votes
Technique - 8 votes
Pre-Shave - 7 votes
IMO (since we're asking) is that technique trumps. Why?
- Lather provides slickness and cushion and yet you could use high end artisan, oil, foam or Arko!!! and still be able to have a great shave.
- Preparation (Pre-Shave) is important, but not critical. You could miss the shower or the glycerine pre-shave soap or hot face towel and the lather you prepare (especially if you face lather) is enough to hydrate your whiskers.
Lather and Preparation are important to a great shave. But technique is critical for a great shave because it comes down to acquiring and using skills.
Skills must be learnt. For without learning certain skills (the critical angle for example) you will never have a great shave (that removes whiskers cleanly, completely and without pain). You can have everything else, but without technique you can't have a great shave.
I guess we can all debate (and we have!) the point, but it all hinges on how you define "a great shave".