What he said^^.
If I were to run clen (especially the first time) I would dose it so I only slightly felt tremors, then i would take that dose again the next day, and the next day until i did not feel them any more. Then I would up it 10-15mg (so i felt them slightly again) and repeat. I would never go over 100mg (even if you dont feel it, it is working). I would also tapper down towards the end of the two week cycle. I would also ensure I drink 4-5 litres of water a day minimum and supplement with taurine and potassium to avoid cramps.
If I were to see side effects i did not like, I would lower the dose the next day until it was tollerable.
I havn't used it, so take what i say with a grain of salt. I do however have a friend who is very fond of it and we have discussed it at length and the most logical way of taking it safely and this what he prefered in terms of side effects vs results.