Cities: Skylines

I'm a hardcore fan of Cities Skylines 1 and have been playing it for several years now. One issue I have though is how I go about making a highway system. It seems so complex, I don't understand how I can connect place to place in a reasonable way and I feel like the only proper way to do it is to ravage through regions of my city to make massive interchanges and efficient routes. My strategy as a result is just using 6 lane roads as my "highways" and kinda just avoiding the idea of highways altogether. I'm so bad at it that my idea of creating an on/offramp is retrofitting roundabouts. I'd love to hear people's thoughts on this and also how to get my mind thinking of the right ways to make good highways.