There’s a routine that you need to learn that will always allow you to move off safely:
Prepare - Get the controls of the car ready first. This includes the gears, the gas and the clutch so that the car is physically ready to go.
Observe - Check all around in this order: Ahead, interior mirror, door mirror(s), blind spot (the area that the mirrors don’t show you). Signal if you need to.
Manoeuvre - Get the car moving as soon as it's safe.
Doing things in this order should get you moving away safely because this cuts down the delay between checking and going.
This is something that you need to get into the habit of doing whenever you move off from a parked position, from a junction or even before doing any reverse manoeuvre. Separating these tasks cuts down your mental workload and reduces the risk of any little “surprises” just as you move out into what you thought was an empty road.
A word of caution: Any signals that you give are only to show others your intentions. You have to make sure that when you move off or emerge, it doesn’t interfere with the progress of the people around you. If they decide to give way, fine, but signals don’t give you permission to do anything.
If in doubt – wait!
More driving advice on driving can also be found here: