So.. Where do you find gold?? Well, creeks, rivers, and water run off's are some of the best places! That's not to say that they are the only places though! There's ancient rivers that are long dried up now that are known to carry VAST amounts of very course gold... more on that in another post perhaps. For now lets focus on finding gold in rivers and creeks.
First things first. The rivers and creeks are not where the gold is coming from! They are where the gold collects! The water from spring run off, floods and landslides all wash gold into the stream bed for you to find later. The gold we find in streams are called "placer deposits". Placer gold is gold that's traveled from its original source - AKA the lode. The further the gold travels the more rounded and smaller the pieces become. With that in mind you can zero in on "new" course gold. If you're finding quartz stone mixed in or even attached to the gold you are very, very close to the source.
Some people like running around with a shovel and gold pan like a chicken with their head cut off! It's not the best method in my eyes, but it can be an adventure and it's not a boring systematic way of doing things. It's a "fly by the seat of your pants" way of doing it and if you've got the prior knowledge and some good intuition it can pay off! I think every newbie tries this once before getting frustrated with poor returns or hit and miss gold finds that don't make any sense.
If you really want to locate a pay streak, the best way is to do a grid system or at least keep it linear. Try the following and see if it works for you.
Find a section of a creek you believe to be gold bearing and look for the high water mark. The high water mark is a good indicator of where the water was during the spring flood season. Those spring floods load and shuffle the creek (hopefully) with gold.
Highlighted in red is where the high-water mark ends. Highlighted in blue is a good place to look for gold. There's lots of roots and it's on an inside bend just after the apex where the water tends to move slowest and even pool around the peninsula.

Here you can see the path that gold and the heavier materials will follow along a stream.Once you have a rough idea where all the concentrations of black sand are grab your pan and shovel again. Go to the spot in the creek (or outside of it if the water is low) and begin panning the area closest to the center of the creek where the black sand levels began to drop significantly.
If the creek is an active gold bearing creek this will be your most likely spot for a pay streak! Continue sampling with your gold pan, and if thing are beginning to look good it's time to move in the heavier equipment like a sluice box where permitted.
If you're not finding much or anything in that spot move down or upstream to another spot and repeat the process. Several factors might be causing the gold not to collect there. For instance there could be a slow spot in the creek up stream where the water loses its momentum and most of the gold gets deposited there! It's also possible that in the spot you checked the water was moving too fast, however if that is the case there should be very little black sand present.
...And remember the old saying: "Gold is where you find it"! It's worth mentioning though that it's best to start looking in areas where other people have found it before!!