Started with 401k savings with first real job out of college 1987, and have been almost 100% stock market mutual funds until about 1 year ago when I reduced to 70/30 mix. Also consolidated several of the old 401k/403b accounts into self-directed IRA at same time as the allocation change. Never did much after-tax savings until I sold a house and received a big cash infusion; up until then I was just rolling extra cash from house sales into next bigger nicer house purchase.
The main thing I did right was continuing to do the 401k/403b savings, and always putting in at least enough to get maximum company match. Also have stayed the path of mutual funds for most part, only individual stocks were those as part of company match given in company stock.