What software do you use on the backing tracks?
It is a great source of good quality and free backing tracks.
To make them myself, I use Pro Tools 11 and a midi interface for digital instruments. I usually try to find a good midi version of a song. Sometimes it has everything you need, then all you have to do is add your plugins for each instrument type. Usually the midi file lacks all the instrument parts or something like that, then I have to add the missing parts, or fix the arrangements. I have enough backing tracks to do at least three sets of songs.