first of all, you probably don't want to work hard to make a good save, so you use console commands! press the "/" key and tab at the same time and a menu should pop up, now type in or Copy and paste UnlockAllResearch true This lets you unlock all items and dispensers (look through other guides for more commands.)

Next you can decorate you rooms or save however you'd like, and that's that!

So for starters, you should only breed beta dogs together, the beta head gene basically never shows up if your cross breeding beta and normal dogs.
Here's one just for you:

64D80C<8CF40F=5D=^F0=7369C4dAF^00E9;8^g333a9E58l:81C2nFDFT4DC289=BBt3FFAD92aB286499;C4=<EA1678cacCDD8a8F6ra^F6ccuaFBD8:3^<<5=b8<A88a;E;2F23:1E8AaBD<0:cE0:32C0F7423E2Cg1344B732069a5bDF0250.3a^1C83^9CbE93C31:C1D1^3d1ADDb7e1Fc400U4c<L430182<b4C^.5o86160AC7:b0=aEo4:73Ca881981Cf262b9aa^Abb3=47A^1b09A0B28B72Ca1b03804o9:9

Now for breeding! first of all if you see a beta dog, always take it. It's pretty rare to see a beta dog even if your breeding two beta dogs (even if its on the first generation, you can still mutate it).

Also, when you dogs become adults follow these steps:

• Store it.
  
• Copy the dog code and import it itself back in.
  
• Release the original (this erases the gut flora).
  
• Name the copied one something like "cleared" or anything, so you know its gone through the storage process.
  
• And you good to go!