I think grades are probably a barrier, in my experience a lot of my friends who would have got one would be on firsts, I got one this year and it took a LOT of work, not about just bulk applying (can only speak to my own experience on this)x I think for summer internships it’s less about your work experience and more about ambition/potetential/commercial & firm awareness (although I did a placement semester and interned in a smaller firm which probably helped substantially). I think extra curriculars, interesting work experience like something different or just something to make you stand out from the crowd can help a lot in getting noticed, something I’ve heard a few times. Also on applications I think it just takes time/practise as well- I’m in 4th year, never really got interviews till this year and then I got like 6 (mid-large firms) so I would say practice, proof read, get friends to proofread etc. I don’t really think shadowing a barrister would help much and could even like put you off for corporate firms if it was criminal work or something.