Straight answers
How do I stop running out of time on the SAT?
Each module is fixed: 27 Reading & Writing questions in 32 minutes is about 71 seconds each, and 22 Math questions in 35 minutes is about 95 seconds each — and you get two modules per section, so 54 Reading & Writing and 44 Math questions overall. Running out of time is almost never a reading-speed problem; it's usually a few questions that quietly ate three minutes apiece. The fix is a hard personal cap and the discipline to flag and move on.
Set a cap slightly under the average — say 60 seconds for Reading & Writing and 80 for Math — and when a question passes it, make your best elimination, answer it anyway, flag it, and go. There's no wrong-answer penalty, so a flagged guess costs you nothing and buys time for two questions you can actually finish.
Within a module you can move freely between questions and revisit anything you flagged, but once you submit a module it's closed. That's what makes the flag-and-move habit safe: the questions you skipped past are still reachable, right up until you submit.
Diagnose before you drill. For a week, note which questions blew your cap. If it's consistently one question type, the problem is a skill gap wearing a pacing costume, and drilling that skill fixes the clock. If the slow ones are scattered, the problem really is decision-making — you're re-reading and second-guessing rather than committing.
Practice under a real clock, not an open-ended session. Untimed practice builds accuracy but trains no pacing at all, and students who only practice untimed are routinely surprised on test day. Even short drills should run against a timer so the sense of pace becomes automatic.