With slow speed film you may not
be able to use a smaller aperture unless you have a tripod.
If your subject is moving, even a tripod won't help.
Set up three or more objects like the photos here.
Set you fstop at its widest setting (f2.8 on most cameras), focus on the center element and shoot.
Now set your fstop on the smallest
setting that will allow you a shutter speed of 1/60 or more ( unless you
are using a tripod, then you can shoot for as long as necessary) and shoot
it again. If you have a preview button this is the time to use it.
The preview button allows you to see through the actual aperture you are going to shoot at and you will see the elements come more into focus.
Now I want to compose a shot that will blur the foreground and keep the rest of the objects in focus. You will need a close camera position and a wide aperture, fast shutter speed.
Next lets have the object in the foreground in focus with blurred background objects.