Under the new Sustainable Development Goal agenda, gender equality and education are important concerns. The achievement of gender equality requires girls, boys, women and men to access their right to good quality education and training throughout their lives. Education can empower people to participate actively in their societies, access better economic opportunities and build healthy, happy lives and communities. This updated and expanded version of the Gender in Education Network in Asia-Pacific (GENIA) Toolkit is designed for use by gender focal points and education planners and implementers. It introduces key concepts and theoretical debates, and outlines practical approaches for mainstreaming gender equality throughout the education system, and within education policy. The toolkit is designed to be used selectively, depending on the user's needs. It can be used as a self-study tool. Readers can select topics that they have identified as priority learning areas to help them improve their own understanding and practical capacity. The toolkit can also be used by trainers to facilitate training sessions. Trainers can choose tools from the kit that best match the needs of their trainees. It may be useful to conduct a simple pre-training needs assessment to help you identify your trainees' experiences and strengths, and the areas they most want or need to learn about or gain confidence in. Trainers are encouraged to adapt the materials. Each tool provides useful information, suggested activities, and short recommended reading lists. References for sources cited in the training are provided in endnotes. Trainers will need to decide how much information to share with trainees, and design training sessions with a good mix of presentations and active learning, so that they demonstrate learner-centred, inclusive approaches to teaching and learning. This toolkit -- as the name suggests -- provides a collection of tools for trainers to dip into, rather than a prescriptive training course that needs to be followed step-by-step and word-for-word.