I keep track of the name of the orchid, from whom (or where) I bought
it, and its condition upon purchase. Quarterly, I note each orchid's
condition, top and roots. I note when I repot an orchid, its condition,
the media that I repot it in (S/H or other), when it blooms, and the
quality and number of the blooms. I note when I've won an award and the
source of the award (regional show, monthly meeting table, etc.). More
recently, I've made more notes on "outside/inside" for the summer and
where the plant is in my growing area in winter: natural light, HID
light, or flourescent light. (Alas, I do move plants around a bit--one
of the best pieces of advice I ever got was this: If it doesn't
flourish, move it.)

I also note when an orchid dies or when I've given it away. I have a
special category of "Died, Donated." Actually, the "died" category can
yield some very useful information--When I reviewed my list, I found
that ALL the orchids that I bought from a certain vendor died--Lesson:
don't buy from him again. In addition, I discovered that all my phals
seemed to have a high winter death rate in a certain growing
area--Lesson: Don't put them there again. I've discovered that the
transition from bark media to S/H is better at some times of year than
others.

No, I don't track watering because it varies so much--this week was
hot, last week wasn't, etc.

One thing that I've started doing is tracking plant divisions. What's
really interesting is to put one half in S/H and one half in bark media
and then compare their progress. For the Catt family, at first the
bark-media half does better, but after a year, the S/H half has
leap-frogged the bark-media half.

Anyway, for me, a DB has been a good way of helping me identify trends.
If I were more organized, I'd do fertilizer studies.