What I do is I have a second layout just for symbols which I toggle with Alt Gr using my right thumb. This way I can stay in the home row and accessing symbols is almost as fast as letters. You'll need a wide layout with 12 home row keys for this to be comfortable though (my right index rests at the l instead of j).

As a bonus I map Shift to the right Win key so that I can press it with my thumb as well. Using the thumb for Ctrl is also doable but it's a little annoying when you need to use the same hand for the combo.