Guidelines for Better Layout
Here are some simple PCB design guidelines that can help you create better board layouts.
Routing: If you are using a two-layer circuit board, it is one of the best way to route one layer horizontally and the other vertically.
Trace angles: If you are making an RF circuit board, you should avoid 90 degree angles on your PCB traces. Besides, 45-degree angle looks more professional, so you’d better design 45-degree angle at the beginning.
Visual check: When you have completed your board, it is very useful to print your board on paper and check it for any problems with connectors and such.
Use labels: Your components should all have labels with name and part value printed on the board. A useful rule-of-thumb is always to label connectors that are to be connected to the outside with descriptive names. Add names for each pin on a pin header.