For webApps, reserve a keyword to pre-fill your forms so testing doesn't require a log of manual data entry.

The first time I did this was for a system that required you to enter data on multiple sequential pages.  You were not able to get to the 5th page without entering information on the first 4. The data entered wasn't that important, but you needed to ensure you added the correct inputs for the validation.  It could take a couple of minutes filling out these pages to get to the page you were testing.  The time loss and distraction was quite annoying.

We added a obscure query string that the base page would look for.  If present a method would be called to pre-populate the form and set focus on the appropriate button.  All you needed to do was hit Enter through the pages until you got where you needed.  It saved a TON of time.

In our case we had static code assigning values.  Multiple records in the db with the exact same information can cause it's own problems.  A variation on this approach is to use reflection or random string functions to assign values.

There are a few caveats. Add logic in your pre-pop methods to check for the current environment.  You definitely do not want this to work in PROD and probably do not want it to work in the environment directly preceding it.  Don't rely on that check to be in a config file as those have been known to exist in the wrong environment.  Don't over-rely on pre-filled forms until they have been tested completely.  "Happy Path" testing will produce more errors later.