Create a “Doing business as” for rental property

[Layla Win]

Hi all, 

I'm currently living in Seattle while renting my house out in Houston for the past 4 years. My income tax rate is pretty high since I have income from a full time job plus and from rental property. I'm thinking of itemizing next year to deduct business related expenses. I would like create a "doing business as" to have a business name for my sole proprietorship and to open a business bank account. I'm not sure which state to file the DBA with Texas or Washington? Thanks in advance for your advice.