I'm bringing it back to basics with this pose because we see it so often in yoga class along with downward dog and it's good to have a refresher. Basically the key with this pose is setting the foundation right. Be sure the front foot heel is in line with the back foot ankle. It feels a little awkward, but it gives a nice stretch in the back hip flexer and along the back calf. The other major key point is making sure the front knee doesn't go over the ankle to ensure the safety of your knee joint.
As for the arms, there really are no rules. I'm showing a basic warrior 1 version here, but you can lift the arms (just make sure shoulders are relaxed away from your ears) if you want a little more of a challenge.
I'd say to give this pose at least seven deep breaths before moving on to the other side. It's a total body stretch (when your arms are lifted), and perfect for everyone from a total beginner or a seasoned yoga student. Give it a try and let me know how it goes.
PS- If you feel like sharing, is there a pose that gives you trouble that you'd like for me to break down? Tell me in the comments section below!
PPS- How to do warrior 2.