So you just bought The Castle Doctrine! Congratulations on your decision to protect your home and loved ones with a state-of-the-art do-it-yourself security system! With a little hard work and a few simple steps, your wife and children might not be bludgeoned to death!
Here are some simple tips to avoid a massive rage induced cornea which is common among new players.

1) You will lose your first 10 or so houses before a good one is up and running.

Your first goal should be to learn the items that are available and how they work together to make traps. I can’t stress this enough. It’s very likely that you will spend a long time on your first working houses only to see them burn to the ground in a testing area.
Consider your first few houses to be drafts. These are lessons learned the hard way in how trap mechanics work together. Also, I learned my best tricks by dying inside other houses. Make sure every death teaches you something.

2) Test with indicator lights and Chihuahuas.

Once I did this, I was able to build more complex houses. This step allows for more precise testing with very low risk. There is a reason we see this mentioned in the trailer. If you ever die during testing, this is what you are doing wrong.

3) Take notes on EVERYTHING.

If your house has several different paths and only one leading to the vault, you NEED to have this written down. The cost of forgetting and going the wrong way is too high even if you aren’t the sort who is prone to making this kind of mistake.
Also, this is needed for scouting. That’s robbery 101.

4) A $2000 starting house does not work.

Spending your entire starting budget down to the dollar will leave you with zero dollars left for others to steal. This means no one will try to rob your house and you will collect zero bounties. Having a zero balance can only work if you plan to go out and earn money buy successfully robbing other house.