Howdy Jim, welcome to Aeclectic Tarot!
I also use the 3-card spread, one of the things I like about it is it's flexability. As already mentioned, the Past-Present-Future is fairly common;
....1....2....3
1 = past
2 = present
3 = future
This is the way I do it anyway... I also use a variation as a "daily" reading;
1 = beginning
2 = peak or main theme
3 = ending
However... I find that for general readings, I prefer to expand the 3-card PPF to a 5-card;
...1...2...3...4...5
1 = past (couple of months)
2 = more recent past (few weeks)
3 = present
4 = near future (few weeks)
5 = future (couple of months)
I generally find that this gives me good insight to an issue or question over a period of a few months. Then if I need to delve further, I can simply add cards to make it a 7-card or 9-card spread, though I haven't tried more than 9-cards, I suppose it would be possible.
I still use the Celtic Cross, but have modified it to suit my needs. There is a thread on this at;
http://www.tarotforum.net/showthread...&threadid=9708. This thread shows several excellent variations of this venerable, old spread. Also, if you haven't already discovered it, you might want to browse the
Tarot Spreads Forum, you will find many discussions on various Tarot spreads which you might find useful.