For relaxation I found more effective lying down and do a body scan meditation.
IMHO posture, meditation style and so are very personal, the best approach is to try different combination and find what suits you.
I used to close my eyes but nowadays I fell more comtkeepibg my eyes open and judt either look at a picture or a tree outside a window and focus my thoughts.
In the evening when I try to go to sleep, I am going to try laying still, closing my eyes , and quieting my mind using the Sleep Meditation MMF routine.
Depending when I meditate, in the mornings I sometimes sit in bed supported but not leaning against pillows, sometimes on the floor either on a yoga mat or a bolster. I always meditate with my eyes shut, but after this question I will try with my eyes open!!!
I kinda like internalising so close my eyes, but hey it’s always good to explore.
I sometimes go without music line when doing gratitude, sometimes use a full moon guided meditation and sometimes I use music. Often depends what my purpose for meditating is!! If I feel I need a bit of help I’ll use someone else guiding me, there are great YouTube channels and websites to help . My suggestion is to explore 🙏🏼
I’m starting to meditate like five minutes under the water after a shower in the morning, that gets my day going more focused.