Here are some tips for circuit board design:
Design in Package Flexibility into Your Next PCB tells that to err is human: to order the wrong component foot print is just part of engineering – it happens to us all who work with hardware. David Cook has a solution that could save your bacon. He shows you how to design multiple footprints into your board to avoid the most common mistakes such as voltage regulators with different pin-outs than expected.
PCB Design Patterns web page has a few tricks and tips that from prototype to production PCBs to provide flexibility on parts, easier assembly, and faster circuit testing. It shows that PCB layouts featuring a few extra holes and a little bit more copper can increase flexibility, speed installation, and improve reliability of your printed circuit boards. You can find following tips: Flexible Voltage Regulator Layout, Choice of Trimmer Potentiometers, Choice of Capacitors, Error-Free Part Insertion, Button Choice, Faster and More Reliable Soldering of Through-Hole Parts, Solder Mask Issue, Copper Fill to Reduce Heat and Increase Efficiency, Wire Loop for Test Probe Hook and Traces.
Here is one example: Universal layout for three-pin linear voltage regulators that can cover practically all TO-220 and TO-92 packages regulators.
Universal layout for three-pin linear voltage regulators