First grandchild... Best way to fund their future?

I love my stepdaughter to pieces, but she's \*not\* fiscally savvy or responsible. She recently had my first grandchild and I want to set him up for the future. I am not wealthy, but I am in a decent position. I want to set up an account that I can manage for his benefit and continue to add to annually for him. I also want his parents and/or other family to have the ability to make contributions. I am split on the idea of a UGMA or a 529. Either way I would likely split the bulk of the investments on VOO, VXUS, and XLE. Are there any other plans that would be worth investigating?