I would do a savings bond, they are safe with no risk involved and some of the series (IE: EE) yield over 5.00%. The longer they (whomever you give it to) wait to redeem it the greater the value and interest they earn. It’s a pretty traditional way of giving a new born or child “money”
Get an investment oriented life insurance policy on Dad, and make it a regular gifting program.
Not only will it be able to build a fund for education expense, it will guarantee the money will be there if dad happens to die or become disabled.
Putting such savings on a regular basis into such an account will allow Dad to take advantage of dolar cost averaging into a stock market type of account that has the added benefits mentioned above along with tax sheltered growth.
I suggest you the ETF IOO.
I am a Portfolio Manager with over a decade of experience in the Stock Markets.