Here’s an excellent introductory short (6 minutess 37 seconds) video by my friend Will Ross on Septuagint lexicography from the Daily Dose of Greek vlog. He helpfully introduces the theme, and illustrates well by showing differences in approach in the two main Septuagint Greek lexical (Lust, Eynikel and Hauspie, and Muraoka). Worth a few minutes of your life!