I would also be careful in Yakumo Temple. It's better as a ryou farming place. Kyoukotsu's lair and Gedomaru's hideout are easier and the former is a great grinding spot. Ankan Forest is extremely easy to solo, even on Hell Mode at sub-30 levels (was doing it at 25), but lower xp payoff per run.
Once you open it after Yellow Dragon Spire, Shinoda Forest is going to be your primary grind spot.