I contributed to two articles on LoyarBurok where a group of five of writers shared our views and advice to law job applicants. This was targeted at applicants for pupillage or for junior associate positions, and we shared our tips on the making of the application as well as the interview itself. Definitely worth a read.
A lot of the tips in there sound a bit basic but time and time again, I see the same mistakes and the same weaknesses cropping up in law firm applications. Recently, I find certain covering emails lacking in formality e.g. “Hi, I am Joshua here” (which is also grammatically wrong) and in another case, I received a Word copy of a CV which still had its changes marked out.