1. Use a tripod, especially if you're shooting at night
2. Use an f-stop to give you maximum depth of field (like f/16 or f/22)
3. Focus on a very distant object in the scene and take the picture.

Imagine a scene with a river in the foreground, trees in the midground, and mountains in the background. Stop your aperture down to a tiny opening, then focus on the mountains. The mountains are not infinitely far away, but they are far enough away.

Take a few shots and check your results. If you don't get what you're after, then focus on something even further away and keep trying. You may need to manually focus to get the desired sharpness.

If you're shooting at night, a tripod (or hard surface) is a must to hold the camera still. With such a small aperture, the shutter speed will be very slow (i.e. multiple seconds) to allow enough light into the camera. And any camera shake will ruin your shot.

Good luck!