Take the object you want to change size of and Press Shift ] to make it bigger.
You can shrink objects down to one tile by using Shift [ or using Control Z to undo your changes. The controls for this are a little wonky, so experimentation is recommended.
I do however, like changing households better in sims4 than in sims3. To fully edit a Sim in Create-a-Sim, type cas.fulleditmode with Testing Cheats On.
Before anyone takes a slice, you can click and add candles again and repeat for other sims that are visiting - otherwise, you need another cake.
You may also milk Cow Plants that have killed Sims to get a potion that increases a Sim's lifespan.
Shift-Clicking Objects allows you to reset them, should something get stuck or broken.
Here are the things you can do with testingcheats - note that this command is also necessary for the extra cheats further down.
Shift-click on PS4/Xbox Consoles - Shift clicking on xbox/ps4 is obviously not possible.
To fully edit a Sim in Create-a-Sim, type cas.fulleditmode with Testing Cheats On.
This will let you change the gender, traits, everything, and is much more powerful than the scaled down version you get without typing this cheat. Shift-Clicking NPC Sims will allow you to add them to your household or reset them if they get stuck.
It's listed above but bears repeating here: sims.give_satisfaction_points gives the selected Sim an amount of satisfaction equal to what you enter.