I think that rest and relaxation is important for everyone, but more so in my opinion when you have a chronic illness or disability.
For me rest doesn't replenish my energy store but it just gives me that pause in the day to stop for a while before continuing on with activities, including very low-key ones (which still uses up my energy supply).
I have M.E so resting is important to prevent my health from becoming worse and with my migraines it just gives me some peaceful time to stop and close my eyes and give my brain a break from lots of stimuli.
When I used to rest I used to use my rest time to listen to a podcast or audiobook, but then I realised that for me that was still stimulating me and it wasn't't giving me the rest my body and mind actually needed.
Personally I physically enjoy laying in the quiet, but my mind tends to wonder so I find it hard to settle down properly.
I've now found a good balance with my rest periods which are built into my daily routine to ensure that I get a good balance of activity and rest. When I rest now I sometimes use the time for silent contemplation (as part of my faith). I also do at least one mindfulness meditation each day.
I've found YouTube good for mindfulness meditations as (a) they're free as opposed to a lot of apps that are out there and (b) there's lots of choice on YouTube to find the right mindfulness meditations that suit me as they're a very individual thing. One person may prefer body scanning or progressive muscle relaxation (with this one I find tensing my muscles too painful) whereas for me I enjoy colour meditations, visualisation and breathing exercises.
The other thing I do when I have a rest periods is listen to relaxation music. At the moment I'm using a couple of apps for this which offer sound effects like sounds of a woodland or rain in the city and I can just lay on my bed with and eye mask on and listen to that for a while and I find it very soothing. It stops my mind from wondering as I can anchor myself and focus on he sound effects. I've also found it good for anxiety and my symptoms too especially pain and my involuntary movements as I can focus on what I'm hearing and add in some breathing exercises and though it doesn't fix or take away my symptoms it does help to deviate myself from over focussing on them. I can also pair it up with some simple breathing exercises which I find helps to ground me and keep me in the present moment.