I was going to say using the wrong colour of foundation but being Indian myself it's hard to find the right colour of foundation when there isn't an SA to help you. The only time I've found a decent High Street foundation was when the SA helped me and it's a nice Bourjois one. My other one is a YSL one and both work just as well as each other but YSL smells nicer. It's difficult to find the right shade sometimes because not many High Streets have a wide range of colurs, Maybelline are really good at getting a wide spectrum of colours. Also, I don't know if it's only me or if other people feel this but I would like more help on how to choose a foundation that is right for me, the only thing that works is the "apply to face" test and I feel really conscious doing that.
Other issues that I have noticed have already been mentioned, especially the super dark lip pencil, the lady who used to thread my brows was notorious for this. She would outline over her actual lips and give herself the shape she wanted with a dark brown pencil, the funny thing was that she was an excellent makeup artist so I don't know why she did that to herself.
Something I have noticed recently is the misuse of blusher and bronzer of which I'm sure I'm guilty too..