Demi Lovato regrets being so "critical" of herself during her younger years.

The 31-year-old star - who first found fame as a child - has revealed that she wishes she embraced "self-love" at a much earlier age.

Asked what advice she would give her teenage self, Demi told PEOPLE: "What I would tell my teenage self is I would say don't hold yourself to anybody else's standards but your own. And if your own becomes too critical, then look within yourself and try to find that self-love.

"I think it's really important to find self-love no matter what age you are."

Demi has learned a lot about beauty and make-up during the course of her career.

The actress-turned-singer shared: "The best beauty tip that I've gotten from someone on set is to never sleep in your make-up.

"I never did that anyways, but to hear it over again was just really important and kind of stuck with me.

"I never sleep in my make-up. It doesn't matter how late the night goes, it doesn't matter if I'm up until the morning, I take my make-up off and I do my skincare routine and I'm very diligent about it. I'm just past that."

Meanwhile, Demi admits that her relationship with social media has "evolved" over recent years.

The 'Cool for the Summer' hitmaker - who has more than 150 million followers on Instagram - has developed her own strategy in order to deal with online negativity.

She said: "If I happen to see something negative, it doesn't affect me the way that it used to. And I don't know if that's just with age or how many years I've been in the public eye, I just don't let it sit with me the way that it used to. It doesn't hold power over me the way that it used to."