Say: "I need 18 inches on either side of the toilet," not "I need a big bathroom."
Don't be shy when describing why you need a certain feature. Knowing why helps the other person know if the apartment fits. Try to differentiate between "musts" and "would-be-nice" features.
Make sure the expensive modifications are there - ramping, hallway size, bathroom size - but recognize that doors can be widened and light switches adapted cheaply. Under the new Fair Housing Law the landlord must allow you to make your own reasonable adaptations.
Landlords often call in search of tenants. Check display ads in the newspaper for the universal wheelchair symbol. This means that there are some accessible apartments in that building. Look for ads in disability-related publications.
Call the office managers of several real estate agencies and ask for an agent who may have experience with wheelchair accessible housing. Speak to several and then choose only one to work with, so there is an incentive for that agent to find you a home.
If you encounter discrimination, inform the landlord of your rights in a helpful way - don't be adversarial unless necessary. The rights and needs of disabled people are new to some. Many landlords don't know a companion or guide dog isn't considered a pet, or that you're entitled to make reasonable changes to make your apartment more livable. If you don't tell them, they may never know.
Most rental housing that recently went into service must have some units built to accessible or adaptable standards.
If you live in a high-rise building, it's good to have more than one elevator so that you don't get stranded if one breaks. In case of emergency - Is there an alternate accessible exit?
Change of season - When looking at a home in summer, consider the accessibility when there is ice and snow on the ground.
How's the neighborhood? - Check out curb-cuts and access to stores and transit in the area.
Be kind to your landlord - Though it's the law, it's nice to receive a few strokes for being a good, accessible landlord. If there are other vacant accessible units, let people know. If accessible homes were always rented, more would be built.
Don't let initial discouragement trap you in a home that will send you looking again soon. If you're happy with the home, consider a long-term lease.