As far as I understand it the whole point of mindfulness is to become the accepting observer of what is, internally and externally. Non judging acceptance. The precise tool you use to enable you to do that differs from person to person, but in my view anything over complicated.. anything that takes you away from reality in anyway is a different kind of meditation from mindfulness. Mindfulness doesn't have any goals, like relaxation. It often happens as a by product.. but if you are not relaxed the important thing is to observe it, recognise how you are in that moment, accept it, not judge it.. and use your breath as an anchor. That way you won't get lost in analysing, thinking about the future or the past. Just accept whatever there is and let it come, let it go.
On a personal note, I haven't managed to meditate once this week because almost the whole entire time I have been on the edge of a crisis and I haven't felt like it was wise to sit formally with those feelings. Hoping to get back to it when my level of emotional arousal is reduced. There has been too much going on to process.