Browsers could do two little things.
Firstly, when mousing over a link which will open in a new tab, show a different pointer. I get a hand with the index finger extended when hovering over a normal link; it could be that but with a diagonal arrow, like the common "open in new window" badge, for a link which opens in a new tab.
Secondly, in the context menu for a link which will open in a new tab, replace the "open link in new tab" option with "open link in this tab".
As long as links are real links, and not JavaScript devilry, this would 85% fix it for me.