Consider a few factors....
- Do you have a tripod with you?
- Is there a place where you can rest your camera?
- Are there moving things like people walking and stuff that you didn't wanna blur out?

1) If you have a sturdy tripod with you.

- U'll have the option to use the lowest ISO possible along with small aperture like f8 or f11 and slow shutter speed to get some dramatic effects like moving clouds or blurred out water.
- Use mirror lock, turn off stabilization and use a remote cable or self timer to get a sharp shot.


IMG_2081 by vmwt, on Flickr

2) If you have a place to rest your camera like a low wall or on your bag etc.

- Use a low'ish ISO, aperture at least at lens sweetspot to get not-to-long shutter speed to minimize shake from wind or vibration.


IMG_0718_19_20 by vmwt, on Flickr

3) If got people moving or u simply have no chance but to handhold, then you need to resort to high ISO di to get a shutter speed that you can comfortably handhold without blur or to freeze moving subjects.


IMG_1398 by vmwt, on Flickr