In this talk I will first provide a brief overview of multichannel transcranial current stimulation (tCS) technology. After developing the first multichannel tCS+EEG systems in 2010, in 2014 my colleagues and I proposed a methodology for optimization of multichannel montages (Stimweaver), which I will describe in some detail. In particular, I will clarify the importance and challenges of defining a target map and a weight map, and the tradeoffs that are needed for optimization. I will then provide examples and the rationale for using this technology for more focal stimulation, e.g. of the motor cortex or of the dorsolateral PFC, for the stimulation of networks, or for no stimulation at all. Some examples of how researchers are using advanced stimulation include stimulation of networks in diseases of consciousness and of the motor cortex network, and also on the use of EEG-driven transcranial alternating current stimulation.