clover's lowest value treat is kibble... for a while now, i've been taking scoops of kibble and mixing it with chopped up hot dog then refridgerating it. the kibble smells like the hotdogs, and gets a little soft... we use that for 80-90% of his training. next up are natural balance rolls, which are basically another dog food, i use that for most of his other training, it is definitely higher value than the kibble/kibble mix, keeps pretty well so i don't have to worry about it spoiling if i'm out and about somewhere/leave it out for a while, and it can be put in your pocket if needed, without being too messy (tends to dry and get crumbly) ...
i try to save higher value stuff for some of our more intense training sessions, like when we work on reactivity or in high distraction areas. usually in these cases i will bring a combo of treats with me, fresh cooked or canned meats and sometimes hot dogs. that way i can really reserve the highest value reward for something really special. clover's FAVORITE thing is cheese, but it makes him really farty if he gets too much, so i don't give it to him often, lol, i consider it my secret weapon. oh, i also use some jerky type treats, i like to have them around so that new people he meets can give them to him (he is/was afraid of meeting new people) some people see how big he is and are afraid he will take their hand off when he goes for the treat, he's generally pretty good/careful about it but to make everyone feel better, i like the bigger pieces, especially when the new person is a child and i like to have a special treat just for that. the jerky treats are also good "keepers" so you don't have to worry too much about spoiling...
for a while, i was giving him cooked chicken for treats all the time, and i think it sorta lost it's value for him, so i had to work to get him down to the kibble mix, lol he used to just spit the kibble out if i gave it to him! if we were outside, he didn't even care about the NB rolls because it was either too exciting/too scary... now i can actually do kibble outside and i'm also able to mix in more and more secondary reinforcers for him... writing this made me realize how far we've come!