My Sisters project was about to be published so I really wanted to enter something from it. I'd just had a rejection email from another photographic competition, and then a minute later I got the acceptance email from the BJP. The work was so diverse and strong this year so I was quietly kind of surprised – I do tend to be quite critical of my work. The past couple of years I've tried to care less about where my pictures will end up and what will come of the projects and just try to enjoy it, which ironically seems to have got more attention.

In my photography I'm particularly interested in relationships between people – and the relationships we have within ourselves. For me this project began after reflecting on my own relationship with my sister; ours has been a tempestuous one. I wanted to explore my relationship through other sisters and began looking at sisterhood in all its glory and all its flaws. Through doing this project, I think it became more apparent that, as adults, my sister and I have never built up a relationship in the same way that some of the other sisters I met.

I started with a single call-out on social media. I didn't really have a massive aim; I just knew I wanted to photograph sisters. When I put out the first couple of pictures, more people came forward. I found that many of the sisters would introduce me to a new set and so on. I was after as much diversity as possible, but I did struggle to find elderly sisters. I could have kept going forever, but after almost 80 sets of sister photos and interviews, I was worried I was losing track of why I was doing it in the first place. I did find, though, that the sisters in the book were really close – perhaps they wouldn't have been in it if they weren't – and despite their closeness their relationships were not without their flaws.

The Portrait of Britain picture featured six sisters, one a close friend of mine. There are nine children in the family altogether, and I was interested to explore how this dynamic works, especially with five of the girls still living at home. The shot was taken in their parents' bedroom on their bed, which I felt was symbolic of their conception and the comfort of the family home.

When I was a teen I was the one photographing friends at school with disposable cameras. It was my social security blanket. I wasn't academic so I gravitated towards the arts and started studying fine art at Kingston University, but I felt a bit lost in it, and realised I was spending more of my time using my camera than anything else. So in my second year I moved over to the photography degree course.

When I graduated I met a photographic agent who told me bluntly that as I had never photographed anyone I didn't know before, if I wanted representation I'd have to branch out. This is when I started working on slightly more exploratory projects. My work now is perhaps more conversational. The relationship between me and my subject is fundamental to making my images work. It's important for me to let people feel comfortable, as so many don't when a camera is about, so I try to make it as personal and natural as I can.

When I first graduated I was working quite a bit in the music industry. I've not done much advertising work, but recently I changed agents and they are really pushing that side of things. I also lecture, which gives me the steady income and safety to experiment and work on my own projects.

Nan Goldin – when I discovered her work I became obsessed with the emotion and vulnerability of her images. Our work is quite different aesthetically, but conceptually this influenced my largest project, my photographic diary. In 2016 I published the first part, MTWTFSS Chapter 1 (2010-2015). It's all personal, autobiographic elements of my life that capture a sense of the changing relationship we have within ourselves, and it's a project I'll never finish. I think I'll always be using my camera to tell some sort of story of my life.

MTWTFSS was also my first solo exhibition, at the Francesca Maffeo Gallery. This was important as it enabled me to show off a larger scale of work than had been possible in the group exhibitions I'd been in previously. Also, as my work is quite "quiet", it can get a bit lost in a large group show.

Yes, right from starting university in 2005 – I wasn't sure what system to buy, but a friend who was using it said, "Nikon is the best, especially the lenses", so I went for it and I love it. I saved hard for my D3S and I've had it for years, then more recently I bought the D810 for its resolution. I'd love to have the new D850 for its combination of resolution and power!

I mostly use the 50mm f/1.4 and, if I have the space to step back, the 85mm f/1.8. I also sometimes use the 35mm f/1.2.

I also love using my Nikon F100 – my boyfriend bought it for me and I shoot most of my diary work on it, using my prime lenses. I love the grain and tone of film and the surprise element of not knowing what you've captured until you have the film developed. It somehow feels more special. My diary shots aren't planned so it doesn't really matter if they don't turn out – it's just the cost of film that is the issue. I buy the cheapest colour film can find on eBay, I never shoot in black and white principally because I love colour, its different tones and especially skin tones. I love skin – I'm a big fan of the work of the painters, Lucian Freud and Jenny Saville, so colour is very important to me.

I find it very liberating to shoot in natural light, mostly for authenticity and because I love how organic ambient light can be; it so often dictates whether I pick up my camera or not. When I'm doing commercial work I also keep the light natural even in a studio, I think it makes people feel more at ease and less like they are on a photographic shoot. Reflectors are a godsend.

Emotion, empathy, vulnerability and a sense of honesty. Yes, I'm selecting the final image, choosing the expression but, for me, what it's more about is the truth I feel that I've found in the subjects. With the social media and selfies culture, nothing feels real anymore – it's more contrived, all dressing up and pulling poses – so I'm trying get people feeling comfortable enough that I can capture the real them, something a bit more raw and vulnerable. I think some of the sisters appreciated the honesty in the work, away from the more polished representations you might expect.

Try not to compare yourself to other photographers, although we've all done it. I now appreciate more my own style and techniques. The moment I stopped caring about making loads of money from my photography and started concentrating on what I love – my personal work – is when it all started to come together for me. Any success I've had has stemmed from this, so my advice is to be authentic, true to yourself and make work that you love. I'd recommend anyone to look up the Helsinki Bus Theory if they get a chance.