If you are a first year student and you would like to start searching for some placements in the summer, here is some advice and personal experience.
My own journey
I was extremely interested in placements in the field of marketing. Still, as a management student who undertook quite comprehensive training in my first year of study, I was open to any other kind of opportunities that sparked my interest. I knew where I would not like to work in terms of sector, but I did not want to limit my choices.
Although I searched for marketing positions, I ended up in a Data Analysis role (albeit in a company's marketing team). My placement spanned across reporting, marketing, analytics, internal communications and in some months, even customer operations. If I had not been open to any variances in my role, I would probably have rejected this offer (a thing that I would have regretted). I also think that my openness to new opportunities and sectors provided me with the chance to get an exciting position. However, my journey was not easy - I applied for almost 100 jobs before I received a "YES".
Would I do something different today than two years ago?
Start early, be consistent, learn from feedback and mistakes. Try not to be influenced by others - you are in your own lane, and your time will come to shine as long as you put in the work, effort and you stay optimistic.
Be prepared at every point of the selection process. Be informed and read the news (seriously, this is one of the biggest mistakes you can make while preparing for phone or online interviews - researching the company but not knowing the sector).
Be involved in the selection process but admit that you might not be suitable for a specific job - try to think of a rejection as a redirection of your efforts rather than a critique towards your skills and your expertise.
Maintain professional relationships with recruiters regardless of whether you get or you did not get the job - the world is smaller than you think, and you never know when you will meet that person again. Send "thank you" notes after interviews and try to make an effort to personalise them. Be gracious with each and every individual at an assessment centre - from the polite "Good morning!" to the last "Goodbye!" you are under scrutiny, and you need to show your best self.
Ask for feedback — network with people. Attend Careers events before the assessment centre to better feel the company if you have the chance. Check Glassdoor before interviews - you might get a better sense of the selection process. Ask for help from the Careers Service - there are so many resources at your fingertips, and you can receive so much support - even if you just want a pat on the shoulder and a kind word.
Finally, just be resilient and do not give up after you get rejected. This, in my opinion, makes a huge difference.