I do not have electric autopilot or windvane. Most of my voyages have been done without them.
What I have done is to lock the rudder in a fixed position and balance the sails. It worked well for me on many previus boats.
On my voyage to Florida 2007 with a young adept on a 27 feet production boat a Swedish Vega we used a for me new system, “sheet to tiller” it gives more possibilities becoause you got feedback from the sails. Its a cheap and reliable system a few strings and flexible rubber and blocks is all you need plus the knowledge to make it work.
When I left Kinsale Irland there was headwinds for the first days. It only took me a few secounds to find the rudder position. From previus experience I know that its very delicate a question of centimeters or even millimeters on the rudderlines. Still it only took me a few secounds to find .
Later when I got following winds I used the sheet to tiller system down to Porto Santo.
My experience from Duga and Bris and other boats have told me that the further back the center of gravity is, the easier she sails downwind steering herself with the rudder locked. In Porto Santo I added 15 liters of water I moved my 10 kilo Spade anchor back also at sea I mowed 2 of my six 14 kilos lead weights to their aft position. I knew that statistically I would get much downwind sailing in the trades.
From Porto Santo I sailed all the way to Martinique using only locked rudder, no sheet to tiller.
I do not know why this works, but works it does. Maybee it creates more resistance turbulence in the aft end of the boat. Anywhy the boat went like on tracks for nearly seven weeks.
What is also very interesting is that the periods of extremely weak winds when the sea surface looked like oil when the wind was so weak it would not have made an unshielded candel fickle she still keept going steadily downwind. In such light wind sails on bigger boats start to flog and flap not so on Yrvind all was nice quite and enjoyable. I think sailflapping is a scale effect, taller mast gives more perific speeds.