Join Date: Sep 2007
Location: UK, Towy, Tweed, Dee, Deveron
Welcome, & my commiserations on catching an obsession which will dominate you life from now on - least it did mine & quite a lot of my fishing buddies too!
Re casting cache handed or non dominant hand up, this allows you to fish off the bank where you would normally be using a double Spey cast (i.e. The "wrong bank" for a single Spey) and to single Spey cast off your other shoulder. The big advantage being that if there is a strong upstream breeze/ wind you won't end up with a new facial/ body piercing from a size 1 Bartleet, or whatever your' personal favourite choice of hook is, whereas this can happen with the double Spey under these conditions.
It's also handy when you are wading deep water close to the bank with trees projecting out as it places the rod outside of you, that is on the side out towards the river, instead of the double Spey which brings the rod tip & line loop back inside towards the projecting branches - never a happy scenario.
In terms of casts a lot will depend on the sort of lines you are using, are they Skagit heads using water borne casts or Scandi heads or full lines using touch and go casts? Each has its' place, but pick one to suit the waters you intend to fish & work up from there as, at this stage of your' learning curve, there's no point in spending time learning something you won't use.
Good luck, Tyke.