I carry a cooler in the van that contains a lot of spotters. In addition since the cooler gets lazy and never makes it into the home I am cleaning, I also carry a belt pouch (Lows, for carpenters) with the smaller bottles of spotters I use the most.
1) Fels
2) Rubbing alcohol (great for latex paint.)
3) Reducer (Red Vanish, I am trying the new one by Bridge point) and sometime just mix a white cotton cleaner (works great.)
4) Delimonine gel (I use Hell Gel but others are good too. I actually boost it by adding liquid delimo to it.)
5) Rust remover (the one that I found works best was by my local supplier - Pro Line.)
6) A neutral spotter (Baby Blue.)
7) A very high PH spotter for filtration (I still have a gallon of
Prochem's for fire damage that I bought about 20 years ago.)
8) Spot & Boost (Vacaway. Works with ink and on some stains that nothing else gets.)