Hi there.
R was in a bed just before her 2nd birthday, and we had this free the novelty of being in a BGB wore off.
I basically camped outside her door (she has it shut) and the minute I heard her get out, I was in there. I'd simply go in, say R is time for night nights (or what ever your sleepy phrase is) and lead her back to bed. The second time, say nothing, go in and lea her back to bd, any resistence and just pick her up and put her in bed. Rinse and repeat until she gives up. So effectively a cross between Wi/WO and pu/pd.
Now (she 3 next week) if she gets out of bed, I leave her to it. She usually just getting a book Or something. She knows she should stay in her bed and on the whole does. We also introduced the Gro-clock
Just after her 2nd birthday which helped.
Hth
Hena