First thing to note..... everyone is different is what that they need and/or want to wear. I always wear cycling shorts with a shammy pad under my pants because without I get badly chafed. So if you need the shorts use them, and if you don't.... don't.

Most mornings I wear tights on top of my cycling shorts with regular, baggy shorts on top of that, then I change at work. I wear the shorts without the tights in the afternoon on the trip home.

I am also trying a pair of Wrangler ATG pants that I picked up at Target for less that $30 which seem to work well for me. If I had to cycle in less than 40 degrees, I would also wear tights under my pants (don't do that - live in San Diego).