SCA and "snapping for the turn" (using the 1in60 rule) work for me, too.
Doubling the distance off track (if parallel) and turning towards track for 5 mins before reversing half the turn to parallel track used to work in the Dominie - it was just a convenient refinement of the SCA and very easy to remember - even 20 odd years later!
Knowing your g/s in nm/minute makes estimates quite painless -
90 knots = 9nm in 6 mins, 4.5 nm in 3 ergo 1.5 in 1 minute
140kts = 14nm in 6 mins, 7nm in 3, ergo 2and third in 1 minute
Stik