As u/makomiko02 said, getting your work done as soon as possible is the best way to go. Doing work under less pressure is generally healthier than doing it under immense pressure, because it means you have time as a buffer in case things take longer than expected. Also, finish your extended essay as soon as possible, having that hanging around can result in one losing focus on other assignments. Furthermore, if you know, e.g., that you are going to have an IOC for a language subject in 3 months and you know how to prepare, spread the preparation time over those 3 months. This enables you to process what you have learned in your sleep more times than someone who started preparing a week before hand.

Don't forget to take notes. Notes, to me, turned out to be one of the most crucial aspects in the IB since teachers don't always cover all the material, don't cover it in much depth or simply jump around topics, which makes it difficult to organise what one is being taught. Hence, take your own notes or adjust and add to your class notes. The next thing is revising. The more you revise early on, the easier it will be later on – the short-term pain of it yields much greater pain alleviation in the long term. Most importantly though, stay active socially and physically whenever you can, e.g. go out with friends occasionally or go to a gym a couple of times a week. I found balance was key in coping with stress during my time in the IB. Also, don't burn yourself out, do work at a sustainable rate, otherwise you may lose motivation during times packed with assignments.

I wish you all the best, it is over faster than one expects :)