Just as an interlinear can be a crutch, so too can be Bible software. Those wonderful programs that allow the pastor and scholar to search and find new patterns can also substitute for the knowledge that allows us to read well and comfortably in another language. How to avoid this crutch? Don't have any native language Bible open when you are reading Greek for reading practice. Campbell gives other tips as well, but you'll need to read the book.
Chapter 4 deals with the need to know vocabulary. I have a confession to make. I like languages; it's fun to learn the ins and outs of the language (grammar) and just enough vocabulary to understand how the language works. That's the fun part for me. Then the hard work begins. That's learning vocabulary, enough vocabulary to become fluent. That takes time and patience and practice. This chapter gives hints and tools on how to learn vocabulary so that it really sticks. The blog excerpts are especially helpful.
Chapter 5 deals with parsing. I used to love parsing, but I hardly get to do it any more! Parsing is very important to the meaning of how verbs and nouns are used. But it's also important to remember accurately what those different labels mean. Anyway, review the paradigms for verbs and nouns. Write them out once a year, a few a month or something. But keep up with them. And I would add, go over the irregular ones that are common so that their principal parts are easily recognized.