Try these following methods.
Stop start technique: When having intercourse, do it for a minute, when you are near to orgasming, stop and remove your penis. Let it become flacid and loose it's hardness. Then after some seconds, make it hard and erect again and then continue again.
Use condoms: Condoms are not only good to prevent unwanted pregnancy and sexual diseases but also makes you last longer because your penis is covered. Thus this reduces friction.
Use desensitising condoms: These condoms have 5% benzocaine. This is a mild general anesthesia which will slightly numb your penis and help you last longer. However some men do not find these good as it numbs their penis for long time and they can't orgasm. However some men find this to be the best and most helpful. This depends from different people as our bodies are different.
Try Himalaya confido tablets: If it is available in your country. This is pretty effective and gives good results for most. These are Ayurvedic.
Consult a doctor: If you feel that premature ejaculation is a problem in your life then get it cured. A doctor will give you techniques or will give you safe medications.