Never used the liquid,But assuming it's dosed correctly, 20-80mcg twice a day should be a good starting point.
I've found best results when running clen for two day's on and one day off running it for up to ten weeks,using an ECA on the off day's..
Like THICK said, you'll just have to customize your dose adjusting it every fourth day or so untill you acquire that jittery feeling.
Everyones tolerance to clen is different ,so the amount you take will depend on how under dosed the clen is and how much your body can with stand.....