I usually boost my diapers with either style of Goodnites (I have the Pull-Up style as well as the liner type style), as I bought a lot of them for around .20 or .25 each and they absorb and swell a lot for the price.
I usually cut the front of the Goodnite and open up the diaper at the top opening to slip the Goodnite in and then just put the diaper on and enjoy it for quite a while (usually until it's at about full capacity)