Practice, practice, practice!

UPDATE:

Set up for first two: Soft box to camera left at a 45º angle. About 5 feet in the air, angled down slightly.  Reflector card to right of peppers.

Third shot: same but dropped soft box a couple of feet. You can see the change in direction.

Set up for wine glass shot: Moved soft box light so light reflected off backdrop through wine glass.  White reflector card held above and to right of objects for fill.

White continuous backdrop (which is a window shade, $11 at Walmart) for all.

Also, I’ve started a Still Life gallery at SmugMug which will give you all the details on ISO, aperture and shutter speed.