Don't book too many dining reservations.
This could just be because my family enjoys snacking so much, but we only booked one dining reservation for our trip. It was for Goofy's Kitchen due to the fact that they had a lot of food that kids love, and we were able to meet so many characters during the dining experience. Outside of that, we just went with the flow. I had some places in the parks that I knew I wanted to try, but I didn't want to be tied down to my dining reservations, especially if my family was having a good time in one area of the park.
Don't walk all over.
I am a huge fan of avoiding extra walking when necessary at places like Disneyland. I'm still getting in mile upon mile of walking during the day, but I didn't want to act like a pinball machine going all over the place throughout my family's trip to Disneyland. Enjoying each of the lands and themes and then moving to the next area helped my family enjoy each one. I would say that we spent the most time at Disney's California Adventure due to the theming of Cars Land and Pixar Pier, but each family will find different areas of the park that they enjoy. Don't force yourself to move to another area just for a shorter line. If it's helpful for you, try to plan a route for the day. I found success doing that on our visit.
My Final Advice
My last piece of advice when traveling to Disneyland with younger children is to just have fun and go with the flow. I'm a big planner on trips, but I learned quickly that I have to be flexible. Rides go down, lines can be long, restrooms have to be found quickly. My plans eroded just about when walking onto Disneyland property, but that did not stop us from having a great time and enjoying the park. I would encourage you to be flexible, enjoy the time with your family, and even though there are frustrating times, remember that your children will remember the fun times they had with you. Put on those Mickey ears and go have a magical time!