Light-Induced spin state switching has been widely studied over the last 40 years, exploring the different time and size scales. This exploration was performed by using a wide range of techniques which are still growing in resolution and accuracy to face the challenge of the increasing complexity of the studied materials (multifunctionality, nanoparticles, thin films, single domain, single molecule …). All these techniques are well described in various papers and reviews emphasizing their specificities and richness. The aim of the article is to discuss most of these techniques from a methodological point of view in order to be aware of all the cautions to take while using them. The most usual techniques used to induce and record the light-induced spin crossover will be described, complemented by a series of recommendations to be in the best conditions for such measurements. The informations that could be extracted or not from these techniques will also be presented in order to have the right level of interpretation.