I usally shoot mine mid-morning to take advantage of the already high levels at that time of day. This is also before i train to increase my intensity.
the prop in the sust will start to hit after 6-8 hours. The most experience competitor in my gym always shoots his sustanon in the morning before work, so that he can feel the prop when he lifts at night.
I shoot my Prop an hour or two before I go to bed. I read somewhere on the boards a long tiime ago, that its best to shoot Prop in the evening before bed because it helps with growth since you grow when your asleep. I don't know if it really works but I've been doing it ever since.