It is no secret that Instagram stars spend considerable time and effort in uploading the perfect shot, but exactly how much may surprise you.

The "fakeness" of Instagram came under scrutiny after Instagram celebrity from Australia Essena O'Neill deleted her account, which had 600,000 followers, and denounced the artificiality of social media two weeks ago.

Before the 19-year-old quit Instagram, she edited her photo captions to indicate that some outfits she wore were sponsored, some photos were taken more than 100 times to get the right shot of her stomach sucked in and some took 30 minutes to find the right background and pose.

Nine local Instagrammers - six women and three men - Life interviewed say these measures are par for the course.

Some wear sponsored clothing or used sponsored products. Others use make-up, filters and selfieediting apps.

Some also have their photos taken only at certain times of the day to get good natural lighting. For clearer or better-quality photos, some use a DSLR camera.

Ms Vera Mao, 23, who has more than 27,000 followers, has stringent criteria for photos that she uploads.

Says the fashion blogger and fashion buyer, whose posts usually involve fashion, interiors, beauty and, occasionally, food: "The photo that I upload needs to be wellcomposed, have good lighting... colours will be edited slightly to fit in with the rest of my photos on Instagram."

She has "blocked out" as much as two hours for fashion shoots to get the perfect Instagram photo.

Full-time social media influencer Rachel Wong, 22, who has more than 124,000 followers, says: "I wouldn't lie - at times I take more than 20 shots for one photo.

"Sometimes, I ask whoever I'm with to help me pick the best photo... And they always say all the photos look the same."

A tip that Life has gathered from interviews: Take photos in the morning or evening when there is good natural lighting.

Doe-eyed SIM Global Education student Charlotte Lum, 20, has more than 21,000 people following shots of herself against various backdrops, sometimes in sponsored clothing.

She says: "I don't take photos at night, only during the day, because I want them to look bright, colourful and vibrant.

"When I take photos, I also make sure the weather is sunny, instead of cloudy or gloomy, because when there is more sunlight, my skin looks nicer."

All the women have worn sponsored clothes or used sponsored products in their posts.

For example, Ms Mao has used contact lenses sponsored by Acuvue and hair products from John Frieda Singapore. But for posts involving such products, she says she uses the hashtag #sp to differentiate them from her other posts.

She says: "I don't think there is an issue because I never wear any sponsored clothing or use any product that I don't like or is not part of my aesthetic. I endorse only clothes that I love and would buy to wear, even if I were not sponsored to do so."

Most of the women and some men have also used selfie-editing apps to improve their selfies.

Mr Jerome Alexander Chan, 21, a University of London undergraduate who has more than 11,000 followers, has used selfie-editing app Facetune to remove facial blemishes. His account is filled with ripped shirtless shots and photos of him hanging out with friends.

He says: "I used to be insecure and had bad acne scars. But now I feel it's important to be natural and real. These days, I usually take only one or two shots for each photo and take only 10 to 15 seconds to choose a filter."

News reports say Ms O'Neill's involvement with Instagram eventually left her feeling miserable, empty and addicted to getting "likes". While some of the Singapore Instagrammers acknowledge feeling a similar pressure to get "likes" and comments, they try not to let this pressure get to them.

Ms Mao, who usually gets 200 to 300 "likes" a photo, says: "To some extent, we do hope to get some validation from these photos because we spent so much time and effort taking them.

"But I tell myself that I want my photos to be good not because of 'likes' but because I take pride in what I do."