Chances of getting into Cambridge masters and tips?

Currently in my 2nd year of a Law and Politics degree at Lancaster. I have been wanting to do a masters in politics for a while and noticed that uni's don't focus on A-levels or GCSE, which is great for me. I got a 2:1 in the first year, however, I did have a lot of mental health issue, mainly insomnia. I got a strong 1st in politics but law put me down a bit, I am hoping to make sure that does not occur again. Have you guys got any tips on how to stand out, I am currently doing citizens advice and I am quite good at selling myself and doing personal statements. I would like to do a year out before applying, to gain experience through internships and writing articles, while travelling.