Yes to dimples whenever possible. That's what can be a bit frustrating with today's slightly narrower tie widths (ie. not getting a good dimple out of an otherwise great tie). Not always a problem though, thank goodness.
All but my one skinny-ish tie seem to dimple of their own accord. Those giant bloated Duke of Kent / Scott Dipstick ties with the convex blade beneath the knot look rank.
Freckles on girls are as attractive as getting splashback on your pants. Dimples are nice for wider woven ties, no dimples for skinny ones and any old random scrunching is fine with knits and raw silk or woollen ones.