For the past couple weeks I've been following a study routine. Three days a week I practice for the main SAT - that's the reading & math portion - and during my free time those days and the whole day the other days, I study for the Biology Subject Test. I'm still worried about my performance there, but I took a practice test for the main one and got 1310 out of 1600, so that's good.
I intend to keep this routine up until the test, for which I'm now officially registered. I'm to take it at the public school in town, which will give me an opportunity to familiarize myself with the location.