This could be the most talkedabout maneuver amongst new drivers and their biggest fear, when it comes to driving. I have heard of stories how drivers elect to park one or two blocks away to avoid parking between two cars.
The most important thing to consider when attempting a park between two vehicles is safety first.
Approaching a vehicle ahead of you, parked on the side of the roadway should be done and planned well in advance. The beginning of the maneuver should start far enough back. If the roadway is wide enough, check you're mirrors, touch you're brake pedal to warn other drivers that you are slowing down and stopping. Signal to the right, assuming we are parking on the right. Check you're right shoulder, keeping the steering wheel straight. Once everything is safe, gradually move over, and drive in a straight line alongside the vehicles you're planning to park between. Do not attempt to move in at the last minute, towards the vehicle. You should be planning this far enough back to swing in sooner, so you will be going straight along side the vehicle, as you approach the vehicle in front of you. You should have a minimum of a couple of feet clearance.
As you pull along side the spot that you are attempting to park, pause, and make a decision on the size of area. This decision should only take a couple of seconds. Is it big enough for you're vehicle? You should have a few feet extra on both ends of the car. You have to leave enough room for other drivers that may attempt to back up, if they have to clear the vehicle in front of their car, to get out. Once you have made the decision that the area that you are going to park is big enough. Continue straight ahead, and stop, when you are parallel to the vehicle you are going to park behind, and change gears to reverse.
Look out the back passenger window and check if you can see the tail end corner of the vehicle, you are parking beside. If you can see it, this is you're turning point. If not, check you're left shoulder for pedestrians. You shouldn't have to worry about traffic at this point. You're front end is not swinging out. Only when it is safe, roll straight back, looking out the back passenger window, and stop when it comes into view. By doing this, you're vehicle front end should clear the car in front of you, but you still have to check to make sure, when you swing in. It will not work if you're only a couple inches away from vehicle you're beside. You need to be two or three feet away.