voting for plain text or pen and paper. What I've found most helpful is writing down 'predicted time required' next to each task. And then if you run over adding an additional prediction next to it. And if you run under writing how long it actually took. I quickly realized my poor time management was due to habitually underestimating the time certain types of tasks take me to complete.

An additional benefit is if you ever need to establish billing or sweat equity valuation, you already have a log of time put into everything.