Some good recommendations above. From a more holistic perspective, claim drafting in a way that avoids all the pitfalls and traps-for-the-unwary that litter the patent law requires experience and years of reading Board and court opinions. It also requires knowing your art and what examiners in your art unit expect. (As just one example, some examiners prohibit the phrase "configured to...", while others require it, or something like it, to introduce functional limitations.) So from that perspective there is no way to get good at claim drafting except to spend years noting all the ways that others have fouled up, most of the time unwittingly, and then assiduously trying to avoid the same mistakes (or what turned out to be mistakes after courts pulled the rug out from under the claim drafters with new interpretations of the law).