The worst housing decisions you can make

This thread will be an ever-growing catalog of bad housing choices that many people make, either through lack of understanding or out of desperation.

Experts, feel free to send me a private message with other suggestions I should add to the list.

1) Buying a mobile home and moving it onto a rented lot in a mobile home park.
2) Paying your landlord in cash and not getting a receipt.
3) Moving out before your lease is up, without checking to see if your lease allows you to do that. (Hint: It probably doesn't.)
4) Moving out at the end of your lease without telling the landlord you're going to do so. Check your lease - it may require you to notify them a month or more ahead of time if you're opting not to renew. Otherwise, renewal is automatic, and you will be bound for another year.
5) Not making requests for repairs, reasonable accommodations, etc. in writing.
6) Thinking the law allows you to break a lease if you're buying a house. (It probably doesn't.)
7) Withholding rent because your landlord won't fix something. (Some states allow you to do this if you use the money to make the repair, but there is a procedure you must follow.)
8) Not doing a damage walkthrough with your landlord before and after you move in. Taking pictures is a good idea as well.
9) Being on a month-to-month lease and assuming you will be able to stay indefinitely, thereby not having enough resources in savings if you suddenly find yourself evicted.