Reading tips

I'm learning Ancient Greek through the 'immersion method'. Thus far I have read the obvious works at the beginning of the road, i.e. Xenophon, Old and New Testament, Aesop and Lucian. What do you guys recommend I read now, what would be a healthy and manageable step up from let's say Lucian.

PS: I would love to read Euripides, but don't know what I need to prepare myself with beforehand.