Best tips about make Boiled Eggs

How long to boil an egg for make soft boiled eggs (Soft cooked yolk) or hard boiled eggs (Hard cooked yolk)?
How make boiled eggs Without Cracking?
1. Put your eggs in a plastic bag and tie it.
2. Water temperature must not much difference with the temperature of the eggs.
3. Add some salt to the water.
4. The temperature should be adjusted slowly to boiling.
5. If you want to make boiled eggs with soft cooked yolk set time 4-6 minute.
6. If you want to make boiled eggs with hard cooked yolk set time 25 minute.
7. At the end remove eggs from boiling water and rinse with cool water (for easy peeling).