The study of star formation is extremely challenging due to the lack of complete and clean samples of young, nearby clusters, and star forming regions. The recent Gaia DR2 catalogue complemented with the deep, ground based COSMIC DANCe catalogue offers a new database of unprecedented accuracy to revisit the membership of clusters and star forming regions. I will present a recent study of the 30 Myr open cluster IC4665 in which we provide a comprehensive membership analysis and we study cluster properties such as the magnitude distribution, the present-day system mass function, and the spatial distribution. Finally, I will expose the follow-up programs we are carrying on to characterize the coolest members of these cluster, making use of the instruments available at the La Palma observatory and in particular GTC.