We did a Hakone day trip last March. We took the Romance Car train from Shinjuku and it was pretty good, as well as fairly quick as there are minimal stops. We didn't go on an organized tour. We don't speak Japanese but managed just fine. We did the whole Hakone "round trip" (narrow gauge train, tram, ski lift thing, boat, bus) and to/from Tokyo in a single day, which was a bit much. If I'd researched it more before deciding to go, I would've stayed at least one night in Hakone.