For indentation, in the case of VFP, I would recommend to always use tabs, and not spaces, for the following reasons:
Works better with block indent/unindent.
Every developer can adapt to his preference (show tab as 3 spaces, or as 5, for instance).
Slight space saving.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)