A very good question Ruth and one we all have to face, with varying success
In our experience there is no 100% solution with the exception of venues such as Massey Hall where one can pay to become a
member or friend and get advance notice of upcoming concert seat sales. Indeed I get about two phone calls a week from a dear
Canadian lady filling me in as a "friend of Roy Thompson Hall"
and last year by paying a small sum to the Flynn theatre in Burlington VT
having found out I think from their website exactly when tix would be on sale
(a couple of days earlier for members I seem to recall)
we got through to the box office on the steam type telephone at the exact moment and could choose any seat naturally we got
the two front row seats nearest to the centre of the stage.Sometimes life is so very sweet!!
However it seems that especially at Massey the first few rows are held back by the promoter under a variety of excuses so you find later that other people buying at the last minute get seats nearer the stage than your sixth row seats that were allegedly the "best available" when you bought them, pretty infururiating believe me
Whatever it is necessary to check the venue's web site and/or Pollstar or ticket b...'d to try to get the earliest possible news of the ticket release date
I hope that helps a tiny bit GG