PH and TDS meters: How best to use them?

Fellow Growers, I need a little clarification on the use of our grow tools.

I have been checking my Ph only by the using the drops (reagent) and comparing to the chart. It is a crude way to monitor plant chemistry and I don't advise it. So today, I ordered my Ph and TDS meters.

Now I figure that it is best to continue to measure and adjust the ph of the water going into the water jug (soil grower) when I mix that up. Only now, I wont have to guess against a color chart. And when I flush, it will be great to get a really accurate Ph reading on the water flowing out. So I get all of that.

But this TDS meter has me a bit intimidated. Total Disolved Solids. Okay, salts, I guess. Minerals and salts, and overall nutrient strength, right?

Praytell, how you use your TDS and Ph meters, soil growers. What do I get from my TDS meter and how will it help me grow better?

Growing without them seems like balancing a BB. My next crop needs to be just a bit less nerve wracking!

thanks!

gm