This stuff seems like obvious common sense, but having sifted a lot of job applications over the years it would appear that it is not obvious to everyone…
If you are going to apply for a job, put a decent amount of effort in. Firing off loads of generic applications without taking the time to understand what the employer does and what they are looking for is just a waste of everyone’s time. If one of these careless applications manages to get you a job then your new boss is probably also a careless idiot and you get what you deserve.
Read the job spec carefully and make sure the CV you send them highlights any relevant experience, ideally covering all the attributes they have asked for. This usually means customising your CV for every application, particularly if you have been working for a few years and can’t fit the details of all your experience on a single CV.
Write a covering email that pulls out the most impressive couple of reasons why you are great for the role. If you don’t meet some explicit requirement in the job spec, highlight that up front and explain why it isn’t a showstopper.