We did two hikes:
Steminitsa-dimitsana: great hike with both mountain views and lush forest. We visited two monasteries on the way which were really worthwhile. About halfway there’s a bridge with a river which is a good place for a dip. It took us about 5 hours. We passed some people on the first half of the trip and none thereafter.
Vytina, small loop, direction of Elati and back: most beautiful part nature wise, authentic Greek tranquil landscape with olive trees, old bridges and rivers.
I really recommend using the app “AllTrails” – this shows all the possible pathways and tracks your location live. The trail itself is really well marked, except for a small bit around the water museum (close to Dimitsana). I’m adding the local information on the route in the photos.