You could grab like 1 or more pieces of paper, stacked together, and make your own funnel/backboard like mechanism. If you have cardboard paper, I'd use that, since it's stronger. You could use tape to make something very much like the shape of a plastic funnel, or you could just hold it together with your hand. Then when you're done, just throw the paper in the trash.
You can make a funnel yourself out of a plastic water or soda bottle you may have sitting in your car. Using scissors, a knife, or even your teeth, you can rip through the water bottle and make it look like the image below.
Pouring quickly helps, but if you hold the container close to the hole you are pouring it into it should work.
Making a Aluminium foil funnel should work. You may opt out of using foil though and cut the top off a water bottle and pour the oil that way. Also, the plastic and foil may last longer than a paper or cardboard one.
Modern plastic 1 quart oil bottles have the funnel built in. In the old days of one quart cans of oil, you either used a spout or opened the can with a can opener and poured into a funnel.
You will note that on a modern oil container the spout is offset to one side. The design is meant to place close to the oil opening of the engine and once started you simply tilt it up vertical inserting the spout into the opening.
While the use of a funnel may be necessary on some engines because of an awkward oil cap placement, generally speaking using a funnel to add oil is reinventing the wheel, and will cause more mess and problems then it solves.
the other answers are good but also to help reduce the glugging, therefore the increases the accuracy, pour it so half the pouring hole has oil flowing through it. this can be done by tipping the bottle slowly or by turning the bottle so that the longest edge of the bottom parralell with the ground.