We do time out more so for DD to calm down than punishment (although it totally happens for that occasionally when needed!).

I used to sit her on a chair in the hall (one story house) which worked, until my toddler was concerned and kept going up to her. Which set my preschooler off. Fun cycle.

Then I tried her room which worked but my Mom suggested not using her 'safe space' as time out..

So now I use my room. Sigh. I have to hold the door shut, too, because she tries to come out the entire time.