I run 25mg E 200mg C and 5mg Y in my ECY stack.
I take one first thing in the morning with a protein shake, as I find that Y on an emptly stomach makes me feel sick.
It then run an EC at lunchtime.
I take another ECY before my evening workout, usually at 5pm.
There is a big difference in my workouts than if I have not taken a stack before hand. I feel more energized and can lift more with greater endurance if I have a stack 30 minutes before.
My workouts run late at night, from 6pm up to 11pm some nights, so I sleep fine by taking my last stack before 6pm.
I know somebody who has a terrible reaction to Y but is perfectly fine on EC, so be careful with it to begin with, there is nothing worse that OD'ing and knowing there is nothing you can do about it but sweat profusely and feel like you could run a marathon

I also found it to be an appetite supressant which meant I was not eating enough in a day, so I had to force myself to eat at least my BMR.
The great thing about it is the price when you make it yourself, it is so much cheaper than buying a pre-made stack with some fancy label on it.
Be careful as it is very easy to overtrain with all the increased energy that it gives, oh and coming off it can be hell. Lower your dose gradually when you want to come off, as the sudden drop in C can give you the worst migranes.
Drink lots, you will sweat more and pee like a trooper

Enjoy