This chapter presents some of the most influential methodological approaches suitable for the investigation of neologisms. It also briefly introduces the two main corpora employed, the International Corpus of English (ICE) and the Corpus of Global Web-based English (GloWbE), which provide data for the analysis of word-formation phenomena across English varieties in the subsequent case studies. Indeed, although this study is inherently qualitative, the use of corpora allows quantitative comparisons where necessary and the observation of the presence of specific neologisms across different varieties. Moreover, the lexicographic resources employed are described and, in particular, are used to note how lemmas which are assigned a specific label in terms of provenience (from WE) enter dictionaries and become part of the linguistic repertoire at large. Thus, lexicographic reflections are also essential to understanding the evolution of a neologism within and across varieties.