Daysailing? Racing? Short hop cruising? Long distance cruising?

Each of these have their own requirements. I agree that an autopilot is critical for any solo sailing. It is your second crew member. Autopilots eat power instead of food and they need to be fed. For anything longer than an overnighter that has to be a consideration. I have two - hot switchable and additional spares - essential for ocean passages. For a thirty footer a windvane is a good alternative to a second autopilot but there are times, like under power where a windvane just won't do so the electric autopilot is important.

Self tailing winches are also a good suggestion. They make sail trimming a mostly one handed function.

For longer distance cruising electronic charting is a big labor saver.

Basic sailing instruments are needed for any sailing. Depth sounder being the most important.