I find that meditating by oneself is good, but if you don’t balance it with group or guided meditation then you can find yourself going down a certain rabbit hole and it’s difficult to pull yourself out of it. Meditation techniques, beyond just paying attention to breath can improve the quality of solo meditation because they give the mind something to focus on and break its patterns. Ultimately they help to tether it to the object of meditation.
Two techniques I’ve worked on lately are noting and body scan.
Noting is where you think “breathe in” on each in breath and “breathe out” on each out breath. This can help concentrate the mind on the breathing.
Body scan is where you successively bring your attention to sensations in each part of the body. Starting with your toes or scalp and working through. This helps you to check in and I find that checking into your body can help to get you out of your mind during meditation. I believe it’s healing to bring your attention to areas of the body experiencing difficulties that you wouldn’t have noticed otherwise.