The rule I go by is, if everything is looking perfect, don't change anything! You don't want to risk messing up a good thing. But every person is different and issues can come up from the use of different compounds. The more drugs an athlete is using, the more variables there are, and the more chance there is for things to go wrong. I can't say what you'll need, but I can tell you what I do and what some of the common issues are.

I have run test all the way in and I have cut it out. I have run long esters all the way in. I've also switched to short esters before the show. If I use a long ester, I need a lot more AI. For most guys, I think it's smart to switch to prop about 6 wks out, continuing the AI and if you are still holding too much at 3 wks, reducing the prop dose. 

With growth, I've seen guys get really bloated 2 to 3iu. If you happen to have that kind of response, I would cut it out early. Depending on how bloated you get, 2 wks should be enough time. On the other end of the spectrum, there are guys, myself included, that hold the vast majority of GH related fluid, in the muscle. For someone like this, they may want to continue it all the way in. Like I said, if you look good, don't mess with whats working. 

With clen, I would continue running it all the way in. This is usually across the board. I've seen guys and gals have a short period of "rebound" after stopping clen, and beging holding more water when they come off of it. 

T3 can flatten a physique out. If this happens to you, I would not come off of it totally, but I would being reducing it a few wks out, assuming that you are in shape. I would slow lower the dose and see how much you can continue taking without it flattening you out.