+1 on the suggestion to use foam pipe insulation (from Home Depot,etc.). I've used it as a temporary cover for bare bars while fine-tuning brake lever location - very plush. Also good for larger hands. It looks goofy, but you can be creative to disguise it if nec.

Slightly less goofy-looking and more 'finished' is the foam Grab-On Grips product - and very 1970's! https://grabongrips.com/bicycle-grips

Or, I have used Planet Bike gel pads under regular bar tape with good results https://www.planetbike.com/store/century-gel-pads.html