The only wisdom about handlebars I have to share is, choose the bar that best suits your purpose. For example, the bars on my rando bike are very comfy for long days in the saddle, and offer many distinct hand positions. On my race bike I use FSA Energy Ts, a traditional bar that isn't particularly comfortable for 'regular' riding at lower outputs, but provides precisely the right support for the positions I want for difficult moments in a race.

I guess that's kind of obvious, but I found myself for a long time focusing on comfort during mellow test rides.