My second cross-country was from Santa Rosa to Modesto, with a quick stop at Stockton, and back to Santa Rosa. A nice little trip. I think I made a mistake in not asking for flight following before I took off at Modesto. My thinking was that the hop to Stockton is only a few minutes and I would request flight following again there for the flight back to Santa Rosa. The problem is that Stockton was a little hard to see and it would have been helpful to have radar keeping an eye out for other traffic. Alternatively, I could have asked Modesto tower for frequency change to Stockton and called them earlier. Another lesson learned.