I don't recommend this AT ALL, but I used to just keep using nonstop until I had been awake 5 or 6 days straight. I'd finally get to a point where I'd crash as soon as my last dose started to wear off slightly.
Then Id sleep for 2 or 3 days effectively sleeping through coming down.
Like I said, I do not recommend this. The chances of having a psychotic episode increase dramatically the longer you stay up. 5 or 6 days of no sleep is like playing Russian roulette with your mental health.
I only post this to show the potential danger of using stimulants. Some people, like me, will avoid a comedown by continuously dosing until a inevitable crash occurs. People like this should NOT use stims... They are a ticking time bomb.