One point might be to butterfly away Henry Ford's mass-produced automobile. Cars would be restricted to the wealthy for a longer period. After all, after a generation of cheap cars, US soldiers in WWII had an advantage over their German counterparts when it came to fixing jeeps and machinery. Society remains railroad-oriented for a longer period.
Allow the Titanic to complete its voyage and many to come. That way, some of the instability that resulted from the sudden passage of wealth to the next generation would be avoided. There were, after all, rather wealthy people on that ship.
Many threads have addressed the issue of by-passing or toning down WWI so as to eliminate the unstable Versailles Europe. In any case, there is no WWII and the development of microwave radar, atomic power and jet engines is stymied.
In Russia, the Bolshevik revolution does not create the threatening USSR at first; Stalin and collectivization do. Butterfly away this issue.
You will then have a mid-twentieth century without a standing cold war. Developed countries might direct their resources to improving less developed countries rather than to building massive war machines.