Catching up on my reading.
I see that Webb Chiles posted on sheet to tiller self-steering last month.
With the sails balanced, Blue Mistress will usually sail herself for long enough for me to go forward, do whatever is required and come aft again. In stronger winds I put a line round the tiller.
Of course, moving forward alters the balance and I cannot rely on her maintaining a course for too long.
So I will try this and let you know how I get on.