If you have to say it often, it might indicate you have trouble formulating your initial advice in a way that is acceptable to people.

Nobody likes to be told they’re wrong, so it helps to be empathetic about it. Packing your advice or instructions into a tactful and diplomatic approach doesn’t cost you much, but makes it much more likely for your advice to be accepted and implemented. And the recipient will usually end up being grateful for having avoided a mistake. They might even start to look for your and ask advice in the future. And if you keep doing that, he might even consider you a nice person or even a friend.

An arrogant and condescending approach will only do harm, even if you are factually right.