Just restarted playing (only rallying so far for two days) after 3 months of lockdown; got a big blister in my palm.
I usually get them, but this time my skin was too soft and I haven't changed my overgrips either, so maybe I was gripping my racquet too tights. One on the thumb as well.
Also the courts are terrible, after resurficing, like a fresh plowed field...That might have been a factor as well.
Playing daily, the timming is still off, so is movement, to some extend (not enough bouncing and running). At times I also forget to prep properly, or exhale as I start the swing or to follow up properly on the the 1HBH.