Buy fresh eggs
One thing you need to ensure is that the eggs you have bought are fresh. In that case, the yolk will be tighter and you will be able to separate it quite comfortably. Moreover, chill the eggs before you need to use them. This will make the yolk even firmer.
Shell transfer method
Crack the egg from the centre. Although you can use different methods for that purpose, the best one would be to hit the egg swiftly against the edge of a bowl. However, you don’t have to hit with too much force, as that might crack the yolk inside. Hold the egg with the cracked side facing you. Slowly start opening up the crack and allow the egg white to fall into a small bowl. Once you have separated the egg into two halves, keep on switching the yolk into both halves gently, until there is no egg white left.
Wash your hands with soap, crack an egg, and put it on your palm. Allow the white part to slip thorough the space between your fingers and then use the yolk as you wish.
Ask someone to hold the funnel for you. Now, crack the egg over the funnel, so that the white passes down and the remaining part stays inside the funnel.
The separator method is probably the easiest one, as you simply have to crack an egg into the separator and wait for the egg white to pass through the open slot.
Soft drink bottle method
Crack the egg into a plate and squeeze off all the air from a soft drink plastic bottle. Bring the bottle close to the cracked egg and start releasing the grip. This way, the egg yolk will be sucked up by the partial vacuum in the bottle whereas the white will remain in the plate.