Investment Vehicle like a Roth IRA

What investment vehicle would you use if you are ineligible to contribute to a Roth IRA?

I make more than the limit to contribute to a Roth and want to find something similar that would work for me.

I max out my 401K and employee stock purchase plan every year, have a managed account by JP Morgan and manage my own individual stock portfolio. But I’m looking for something relatively safe with consistent returns to put money into instead of the half researched trades I make.

What would your suggestions be?