When choosing (or creating) a Tester Family, keep in mind the type of build you are doing.
If there will be features on the lot for adult Sims only, then there is no reason to have a child Sim or a pet in your Tester family.
If you are building a lot for Sims and horses, then your Tester Family should have at least one Sim and one horse.
The same Tester families can be used over and over again.
It is actually very useful if certain of your tester Sim's skills are high so that you can have them produce things for use in your build, so using the same tester Sim over and over again makes it more likely that that Sim will have the skills that you need.
I have one Sim that I have used for a very long time. I have more than one version of her (and the skills for the various versions in my library are not all exactly the same) because I have a version where she is alone in her household and a version of her with pets.
Here are the steps to make a Tester Family:
1. Go into Create a Sim and make your Sim family have the minimum number of Sims that will be required in order to test out whatever you will have that needs testing on your lot. The Sims can look any way that you want them to, but the choices of traits are important. You can actually use an existing household instead of creating one from scratch, just make sure that there are the minimum number of Sims needed and change their traits as in the next step.
2. Artistic is a good trait to give your Sim so that he or she can paint and sketch and hang this artwork on the lot you are building (IMPORTANT: do not frame your Sim-created artwork if you plan to upload your lot as framed art will not appear in the upload).
Handy is a good trait to give your Sim so that he or she can upgrade your appliances if desired.
Bookworm is a good trait to have (at least in the beginning) so that your Sim can quickly learn skills from books.
3. Choose any other traits based on the lot you will make. For example, if you are making a farm with a large garden, Green Thumb would be a good trait to give your Sim.
4. This step is optional, but very useful. If you plan to do it, you will need to use the cheat “testingCheatsEnabled true” and you will need to use it on the MAIN menu (before going into your lot).
Place the Sim on a lot. While in live mode, go to the right of the treasure chest icon (lifetime reward points panel) and CONTROL click beside it. If you are doing it in the right spot (and if you used the cheat as instructed) you should see the total of lifetime reward points jump by 500 with each Control click.
Load up this Sim with enough points to purchase all the following: No Bills Ever, Collection Helper, Super Green Thumb, Fast Learner, Super Creative, and Fireproof Homestead. There are other really good lifetime rewards that you may eventually want (so you can add stuff like the Hover Bed to your lot), but you can always add more points with this trick later.
