Kylie Jenner used to tell big sister Khloe Kardashian she had to contour.

The 34-year-old reality star revealed that despite her make-up mogul sister being 13 years younger than her - she has always given her advice on how to do her makeup and which products to use.

In an interview with Glamour, Khloe said: ''Kylie is very confident, makeup is totally her world. I have learnt a lot from her.

''I am older than Kylie and she would say from a young age, 'You should really contour,' or make me change certain products I was using.''

The 21-year-old mother-of-one revealed her 'In Love with the KoKo' collaboration with Khloe earlier this month, and the 'Revenge Body' star has admitted that it was easy working with her sister as they ''respect each other in their certain fields''.

She said: ''She just has such a great eye for other people's faces. When Kylie gives you a critique, it is coming from a helpful place; she's not trying to sabotage you in any way.

''She wants to pass on her knowledge on how to apply makeup. When we collaborated, it was super easy for her and I to work together. We respect each other in our certain fields and I think that is crucial for working with anyone.''

Khloe believes the reason 'Kylie Cosmetics' is doing so well, is because the she has ''standout products'' and doesn't just ''slap her name'' on the make-up in her line.

She said: ''If you slap your name on something, and people know it's easy to get things past the 'name', you won't have standout products.

''As a family, we only put our names to things that we stand by and we believe in. I don't think people realise how much stuff we have to keep our eyes on - we never cut any corners. Kylie has done an incredible job of that. Yes, that's more time-consuming but we want to be putting great products out into the world of great quality.''