One thing that our family did for quite a while was journal everything our son did. Mind you, at this time we still don't have a diagnosis other than SPD but we're looking probably the autism spectrum (high functioning end). Through all of our different doctors one thing we did was document what was going on each day. I recorded what he ate and when. I recorded when he went to sleep and woke up plus any naps. I also recorded his moods. I did this in great detail for about a month and then slowly stopped.
What this did for us was not just paint the doctors a picture of what was going situation or family wise but also it gave us some insight as to things we could change. For instance, we realized that we needed to change his meal time when he acted a certain way although he didn't verbally tell us. We could also see that mood wise there wasn't an actual pattern for his outbursts although I can now see it beginning to show it's head before it goes into a full swing but also these go on longer than one day. The doctors were able to see that what we were talking about weren't 'normal' behaviors for his age as well. The things he did and the things he said were out of place and ummm... scary.
It also helped me to see that I wasn't going nuts. I could tell he had mood swings. I could see the developing behavior or lack thereof and I could also see where I might have been inconsistent schedule wise.
I do journal now but that is here on my webpage. Maybe tomorrow I will end up showing you how I did it if I can break out my old book that I kept notes in to show you how detailed I got. Not everyone will go into as much detail as I did but I did relax after about a month or two. I just needed a time frame captured... usually 3 months is a good time frame but I just couldn't keep it up. Days were bouncing into one another and I couldn't keep things straight as one day felt like the next.