One of the biggest error folks make, is not contributing to an employer 401k.
Where my wife worked, only 6% of employees contributed to the 401K, the company matched 80 cents on the dollar.
Half of those 6%, wouldn't leave it alone when they did participate. Withdrawing money for stupid stuff or for buying cars.
I convinced my wife to contribute early on, and to leave it alone, she contributed for around 22 yrs, and at retirement it paid off
extremely well.
So many did not understand that for every dollar you saved, they
gave you $0.80 cents.
At one time I was doing some day trading, with the likes of Netflix, Groupon, Ruger, Facebook, S&W, Twitter, couple of others I don't recall now.
But as long as I paid attention, I could make 12-18% return.
Several yrs ago, I went with a fee based Financial consultant, he makes no commision on trades, I pay a set fee quarterly and he manages it.
I have full online access to the brokerage account he manages for us, I can easily see exactly what is going on, and over 23 yrs it's averaged 12%.
Me likes me some mutual funds.
Its also easy to setup your own accounts at Vanguard, and you have access to a multitude of different low cost MF's.