Can you point out some reference books on literary criticism – from a theoretical as well as practical point of view – to hone and systematize my skills, acquired through first-hand reading of lots of books.
A very good read which is informative and entertaining is, How To Read Literature Like a Professor, by Thomas C. Foster.
Another very good book is Literary Criticism: An Introduction to Theory and Practice by Charles Bressler. A bit more academic, but quite good.
One of my go-tos is "Literary Theory: A Very Short Introduction" by Jonathan Culler. It's great for people who are new to literary theory, or for veterans that are looking to brush up on the basics.
One of the standard introductions for university students is Literary Theory: An Introduction by Terry Eagleton.