most people take about 60-80mcg of clen a day and they take it for 2 weeks. then quit for 2 weeks, then go on for 2 more weeks. This is due to clen's long half life. You can use something like ephedrine/caffiene in the alternative 2 weeks if you want.
As far as cytomel, its hard to say. Some people pyramid while some maintain a stable high dose like 50mcg/day. Some go for low doses (12.5mcg).