I use lots of smoked paprika, cumin, cinnamon and some chili flakes, and I often add in a sprig of rosemary or thyme
we don't like it super hot so when I add the chilli I don't cut it up, I just slit it and hurl it in whole.
Also cocoa is good for getting good depth of flavour
Often use beer or wine instead of stock
ALWAYS sweat the onions and garlic until they are soft, and ALWAYS sear the mince, I get my heavy frying pan as hot as hell and drop in the mince, make it flat and then wait until it's nicely browned, flip it over for the other side to do and then break it up and add it to the onions
Also I put all the ground spices in with the onions and a little extra butter just to cook them off. before the meat goes in,
Swish the stock/beer/wine into the pan that you seared the meat in and all the bits will come up and then tip those into the meat mix.
I also prefer black beans and canellinni or pinto beans. Kidney beans are not my favourite.
Slow cook and leave overnight ideally.