What do you need?
You don't need much to get started with one of my online yoga classes or an instructional video. Some comfy clothing, which you can move easily in, and a mat are a good start for both. Having said that, you'll find videos here where you don't even need the mat and you can do the sitting on a chair. Place your screen where you can see it easily when looking straight ahead (when facing the short end of your mat is best) and you're ready to go! If you're attending a class it's best if you use a computer or tablet rather that a phone so the screen is bigger and it's easier to see what i'm doing. Try to get your camera close enough that you can see me but in a position where i can also so most of your mat and you, at least when you're sitting down.
Take it easy!
First of all - take it easy, start slow and always listen to your body when doing stretches - don't push too far. You shouldn't feel any pain whilst getting in to a stretch or yoga posture. If you do come out of the pose. Yoga isn't about being as flexible as possible. Like with most things, doing a little but regularly is the best way. Over time your body will slowly start to change. So don't worry if you think you're not flexible enough to do yoga (something I've heard many people say) - that is the whole point. The moves we do are going to help you become more flexible and increase your range of movement.
When's best to do yoga?
I'm a morning yoga person - I find it's a great way to get going in the morning and find myself having much more productive days afterwards. But i know mornings aren't for everyone! And yoga can really help at any time of day. If you're doing a full class or a sequence where you're moving around a lot or twisting it's best to wait for a couple hours after eating a big meal. Other than that whenever and wherever! Some of the shoulder opening stretch videos you'll find lend themselves particularly to being done on the go. So why not try integrating them into your practice or rehearsal schedule. I find they can feel particularly good between playing sessions as immediate relief from my flute playing position.