New to kilt wear! Need advice

[Jimmy the Celt]

First of all, welcome!

As for the tartan over the shoulder, you maybe thining either of the belted plaid, where the tartan goes over the shoulder, a fly plaid, or a pipers plaid, which is worn a bit differently. As far as significance goes, I'll leave that to others who know better than I.

[PiobBear]

A plaid worn over the shoulder is just a fashion, with no real significance to it. It's usually reserved for formal wear, and not everyone cares for them; to each his own.
A local Presbyterian minister from Glasgow preaches his Kirkin' service in a matching Lindsay kilt and stole with an Argyll jacket; looks good on him.

[Cawdorian]

My pastor conducts the Kirk'n service in an Hunting Fraser Kilt, a Braemor jacket and vest.