Increase only when it suits how you're feeling. If the amount you're on now is getting results, there's no need to go higher right away.
Studies I've looked at used steps of 2 mg for four weeks, then 4 mg for four, then 8 mg for four. Some participants began at 4 mg while others started at 8 mg, and the main difference was how many sides showed up. My first shot was 2 mg and I barely noticed anything. With no sides so far I'm considering moving faster: 2 mg, then three rounds at 4 mg, then two at 8 mg and staying there. Any ideas on going quicker than the usual 2x4, 4x4, 8x8 pattern?