This article deals with the notion of collocation graphs and lexical networks, which not only represent the visualization of the collocational relationship between linguistic units - these have been traditionally displayed in a tabular form with frequency distributions and association measure values - but also an important analytical method in its own right. We illustrate the use of collocation graphs and networks with two case studies as examples demonstrating the use of this technique in lexicography and discourse analysis. The examples are based on both English and Czech corpora, which we analysed using #LancsBox, a free tool which can build collocation graphs and networks on the fly.