As others have said, it's all in the unweight and the timing. I wouldn't worry about any other techniques at this point if you are a noob to trials. The little double-blip unweight will work when you get it right and the basic technique will eventually come easy for you. I'm a relative noob myself, just having finished my second year of riding. I'm amazed at the things that are now easy for me compared to when I started. I'm also amazed at how much better many riders are.
In the video below, you can see the steps for a basic rear wheel unweight to cross a small log. It doesn't take much - you just need to remove your own weight from the bike so that it effortlessly rolls over the log. When you do this, the rear wheel is much more likely to track straight over a wet/angled log. Note how when the rear wheel does hit the log, the knees are bending and allowing the bike to continue to come up instead of pushing downward on the pegs.
As the logs get bigger, the technique is the same - just bigger.