When i was a kid we used yogurt. Not strained yogurt, normal yogurt (it has more liquid obviously). It was ok. Nivea was also good after the sun exposure. In general i use something from the pharmacy store now, because they are better. And of course i avoid sunburns now. They are bad for the skin and for health in general.

The worst sunburn i had, caused a burn of second degree...

Please avoid sunburns. They are no good.