As a self-employed contractor doing office work in someone else's office, there is probably very little if anything that you can claim as business expenses. You cannot claim the cost of commuting to and from the office. If you provide any of your own office supplies you can deduct the cost. If you buy any legal reference material or books that you need for the work, you could deduct the cost of those. That's about all I can think of. Maybe someone else will have some other suggestions.
