Always keep your limits in mind. There’s no point in trying to start a breath work practice or a meditation practice that’s an hour long right out of the gate, that’s just going to end up being a frustrating and discouraging experience. Know your personal limits, and be realistic. If you’re having a particularly fidgety or distracting day, try doing a shorter practice for that day.
Make sure that you start smaller and shorter, and then you can work your way up to longer and longer practices from there. Make sure that you’re setting yourself up for success with your expectations for that practice.