Here are some business travel expenses you might not know you can write off according to Business Insider. They say you should keep accurate records as well.
Dry Cleaning: Sometimes trips last longer so the IRS says expenses for dry cleaning and laundry are tax-deductible as a business cost.
Calls and other communication: You may already keep track of calls but also keep track of faxes and Internet connection fees if you have them.
Convention travel: Workshops, conferences, and seminars if they have a direct business purpose.
Shipping work material: If you have to send ahead the products you are showing for potential buyers, like a trade show, you can deduct that cost.
Stenographer fees: If you have to hire a stenographer to transcribe legal docs you can write off associated fees.
Computer rental: If you need to rent a computer, you can write off the cost.
Business travel by RV: If traveling by RV can be proven necessary for business, any expenses are tax-decutible.