Hi
In the very early days when I was changing her like 10-12 times a day I would use a bamboo foldup from BB folded in half inside a NB Thirsties cover. I put a microfleece liner too on top of the foldup. The BB foldups are great for so many things that I recommend getting a few. I use them to boost nappies now all the time. And sometimes when she was a bit older and I had run out of nappies because I forgot to wash I would put them inside a S cover and they did fine
Sometimes I would put two inside. I use them to boost normal nappies that dont last long and also to boost the BB one size fitted for night time.
I loved Thirsties covers and also Tot Bots because of the gussets.
For more MCN type nappies I liked the bubblebubs a lot and also the bitti boo fitteds as well as the Tot Bots fitteds
HTH