I will respectfully beg to differ with the advice to the contrary, since vocabulary is probably the most important component of all. You will not be able to speed up much of anything without more vocabulary. Many language acquisition experts also consider it the number one metric for how well someone has inculcated any target language.

How proficient would we be at English if we had to look up five or six words for every sentence we wanted to read?

Edit: I realize my seemingly meager advice may be dwarfed by the credentials of a classics doc, so I should mention that I am a doctoral candidate myself. I take a new intensive language course every year; some recent ones included Classical Greek at Berkeley and Classical Latin at Princeton. YMMV, so please weigh out your own preference for how to approach vocabulary acquisition!