Hi - I'm interested in asking if you do a PhD in a certain technique is it possible to change techniques at a later date (after completing PhD) if it's in the same area (i.e. similar theory and application) of science? I've noticed that most people stick to the techniques they used for their PhDs. Thanks.

it is better to stick your technique but alert on new & other development of that field.

Most people have a few core things that they can do from their Ph.Ds but sticking with the same techniques is not wise nowadays. The problem is getting the opportunity to learn new techniques as you will hired partly based on your competance in the old ones. Just picka postdoc position that has a mix of old and new.