<human>: Condense the text into a few key points

I am currently starting up my own one-man pet-sitting service and am in the process of writing up a contract so I can avoid getting into any significant disagreements about either party's responsibilities. I have a good bit of casual experience under my belt and now that my client base is growing, I'd like to cover my bases with a formal contract. 

While I think I've developed a decent contract including common sources of potential conflicts (responsibility to pay any unexpected vet bills, injury/death of an older or sick pet, etc.), I'm certain that there are several situations which haven't crossed my mind that should be included.
<bot>: What should I include in my contract in order to cover my ass in the event something unexpected happens and potential damages are incurred?