The first trick is you need to find something to be passionate about, and this is hard. You're going to need to do a lot of reading, you're going to need to do a lot of research. If this is a struggle then you don't have to develop a life-long, overwhelming passion for something. You can have a passion for something just for a couple of months, until university interviews are out of the way, you've got a place sorted, and then we can forget about it. It is unlikely that the admission tutor is going to come back six months later and want to talk about it again. You need to get passion across in your application form and in your interview.
Start by thinking which parts of your A-Levels interest you and which part of your future degree course interest you. Start reading, either buying or going to library and reading general magazines in your subject. There are loads of specific magazines in every single area that you can think of. There's going to be engineering, architecture, fashion design, there is going to be a niche magazine for your subject. New Scientist is an obvious one, the science. Go out and buy a few issues and sit down and flip through it and see if anything catches your eye. If there is something that catches your eye just go and do a little bit more research on it. Go and look at what the authors were writing, go back and see if you can get your hands on the papers, go and see if you can find some books on this or find some, a couple of books on this. Ask your teachers because your teachers generally are going to like reading books on their subject. I know that in the corner of my classroom I have piles and piles of science books and general books that people can just borrow to read whenever they want to. I lend these out, and then people come back and swap those like a little science library in the corner of my classroom.
Getting your passion across in your interview is relatively easy if you've got a good subject that you can talk for say, 15 minutes about. But getting that across in your application form, your UCAS form, can seem a little bit harder. There are a number of different way you can show this.
The extended project (EPQ) or extended essay comes in really useful. Most schools offer this, and you can do pretty much anything you like. But if you do it on something that you’ve talked about in your UCAS application, you're killing two birds with one stone, and you're getting your passion for the subject across in your UCAS application. For example, you wanted to go and do medicine at university, there is very little point in doing your extended project on bridges, because that is not going to impress the university admissions tutor in any way at all. But if you wanted to go and do engineering at university, and you did your extended project on some tiny, tiny little bit of bridges and how it revolutionized building bridges across big rivers, then that's the sort of thing that is going to get passion across to your university tutors.
The other thing that you can do is look for writing competitions or start writing for magazines. We're not talking about the big magazines but for example the Young Scientists Journal is run by students aged 12-20, and Keble College, Oxford has a yearly essay competition in theology & religion. These are just a few examples from a wide range. Even if you're not planning on applying to Oxford, getting an award from a writing competition or a mention from this is going to look amazing on your UCAS application form. If you can't find anywhere that will publish it, think about publishing it yourself. I do a lot of self-publishing on YouTube and on my website. If you started up a series of videos or blog posts about boats, and the engineering behind boats or sails and you wanted to apply to do nautical engineering. That would show a long term dedicated interest.
The last way that you can get your passion across is by competitions. Each year there is an Olympiad for each science and maths. You have to do it via your schools, your teacher has to organize it, I'm sure if you go and ask your teacher very nicely, they would help you out.